Ophthalmic Device Molds Formed From Water-Soluble Vinyl Alcohol Copolymer, Ophthalmic Devices Molded Therein, And Related Methods

ABSTRACT

Ophthalmic device molds made from at least one water-soluble vinyl alcohol copolymer, ophthalmic devices such as ocular inserts and contact lenses and including silicone hydrogel devices formed using these molds, packaged ophthalmic devices present in a solution comprising the at least one water-soluble vinyl alcohol copolymer, and related methods are described. The methods of manufacturing ophthalmic devices can use wet demolding processes, or wet delensing processes or both wet demolding and wet delensing processes involving dissolving the molds in water or an aqueous solution.

FIELD

The present disclosure relates to ophthalmic device molds comprising awater-soluble vinyl alcohol copolymer, ophthalmic devices includingocular inserts and contact lenses cast molded using a mold formed from awater-soluble vinyl alcohol copolymer, a packaged ophthalmic device, andrelated methods.

BACKGROUND

In cast molding methods of producing ophthalmic devices, such as ocularinserts and contact lenses, a reaction mixture or polymerizablecomposition is commonly cured in a device-shaped cavity defined by afirst mold member with a device-forming molding surface and a secondmold member with a device-forming molding surface, or a female and malemold member, respectively. The mold members are typically produced byinjection molding a thermoplastic polymer into mold-shaped cavities.Examples of thermoplastic polymers which can be used to make ophthalmicdevice molds include non-polar thermoplastic polymers, such aspolypropylene, polystyrene, and polyethylene; and polar thermoplasticpolymers, such as ethylene-vinyl alcohol copolymers and poly(vinylalcohol) homopolymers. When cast molding ophthalmic devices, afterplacing the polymerizable composition in the first mold member, thefirst and second mold members are placed together or coupled together toform a mold assembly with an ophthalmic device-shaped cavitytherebetween. The mold assembly is then cured to polymerize thepolymerizable composition, forming the polymeric ophthalmic device inthe device-shaped cavity of the mold assembly.

Contact lenses, including silicone hydrogel contact lenses, have beencast molded in molds made of ethylene-vinyl alcohol (EVOH) copolymers,for example SOARLITE™ S available from Nippon Gohsei, Ltd., Osaka,Japan. Molding silicone hydrogel lenses in EVOH molds has been found toresult in lenses having ophthalmically acceptably wettable surfaces.Previously, it was necessary to apply a surface treatment such as, forexample a plasma treatment, or to include an interpenetrating network ofa polymeric wetting agent in silicone hydrogel ophthalmic devices inorder for the device surfaces to be ophthalmically acceptably wettablewhen hydrated. However, EVOH is an expensive material which isessentially insoluble in water. The high cost of EVOH molds cannegatively impact production costs. Additionally, it can be difficult torelease the polymeric ophthalmic device body from EVOH mold membersfollowing curing, which can negatively impact device yields andproduction costs.

It has also been proposed to use poly(vinyl alcohol) homopolymers(PVOH), including modified forms of PVOH, to form ophthalmic devicemolds, including contact lens molds. The use of ophthalmic device moldswhich are water-soluble could be particularly useful and cost-effective,as it could simplify the process of releasing the device from the moldswhile also reducing the possibility of damaging the device during therelease process. However, the use of many forms of PVOH has been foundnot to be ideal for use as ophthalmic device lens molds. For example, asthe traditional melt processing temperature and thermal degradationtemperature of unmodified PVOH are almost the same, it is very difficultto use these materials to injection mold ophthalmic device molds.Although PVOH is water-soluble, it can be difficult to achieve completedissolution of the material, particularly at low water temperatures, andsolutions of PVOH typically do not exhibit stable viscosities, as theygel readily and crystallize when subjected to high shear conditions.

While some modified forms of PVOH have been proposed for use asophthalmic device molds, these modified forms of PVOH still retain someof the undesirable properties of unmodified PVOH, such as, for example,high crystalline content that reduces light transmission through thematerial, slow dissolution in water at lower temperatures, and, whendissolved, significant portions of the material may remain present asundissolvable solids. Further, as with unmodified PVOH, aqueoussolutions of modified PVOH can gel or foam easily, and the materials mayproduce cloudy aqueous solutions due to precipitation of the PVOHmaterial. Although the prospect of an ophthalmic device mold that couldbe dissolved in water would be attractive, these undesirable propertiesmake it difficult to use either modified or unmodified forms of PVOH incommercial production of ophthalmic devices, including ocular insertsand contact lenses.

In view of the above, it can be appreciated that a need exists forophthalmic device molds comprising new types of materials for castmolding ophthalmic devices including silicone hydrogel ophthalmicdevices, for new ophthalmic devices cast molded using molds comprisingthese new types of materials, for packaged ophthalmic devices castmolded using molds comprising these new types of materials, and forassociated manufacturing methods which use these new types of materialswhich can be less expensive and more process-friendly. A need existsparticularly for water-soluble materials which can be used to form moldssuitable for molding contact lenses.

All publications, including patents, published patent applications,scientific or trade publications and the like, cited in thisspecification are hereby incorporated herein in their entirety.

SUMMARY

In a first example, the present disclosure is directed to a method ofmanufacturing an ophthalmic device, comprising: providing at least onewater-soluble vinyl alcohol copolymer; using the at least onewater-soluble vinyl alcohol copolymer to form at least one of a firstmold member and a second mold member, the first mold member comprising amolding surface configured to mold an anterior surface of an ophthalmicdevice and the second mold member comprising a molding surfaceconfigured to mold a posterior surface of an ophthalmic device, thefirst mold member and the second mold member configured to form anophthalmic device-shaped cavity therebetween when combined as a moldassembly.

A method of the present disclosure can further comprise placing apolymerizable composition comprising at least one hydrophilic monomer inthe first mold member or in the second mold member; and assembling themold assembly by contacting the first mold member and the second moldmember so as to form the ophthalmic device-shaped cavity therebetween,with the polymerizable composition contained in the ophthalmicdevice-shaped cavity of the mold assembly.

A method of the present disclosure can further comprise curing thepolymerizable composition in the mold assembly to form a cast-moldedpolymerized reaction product in the ophthalmic device-shaped cavity ofthe mold assembly, the polymerized reaction product comprising apolymeric ophthalmic device body.

In one example of the present disclosure, the ophthalmic device cancomprise an ocular insert configured to contact an anterior ocularsurface, the first mold member can comprise a molding surface configuredto mold an anterior surface of an ocular insert, the second mold membercan comprise a molding surface configured to mold a posterior surface ofan ocular insert, the first mold member and the second mold member canbe configured to form an ocular insert-shaped cavity therebetween whencombined as a mold assembly, and the polymerized reaction product cancomprise a polymeric ocular insert body.

In another example of the present disclosure, the ophthalmic device cancomprise a contact lens, the first mold member can comprise a concavemolding surface configured to mold an anterior surface of a contactlens, the second mold member can comprise a convex molding surfaceconfigured to mold a posterior surface of a contact lens, the first moldmember and the second mold member can be configured to form a contactlens-shaped cavity therebetween when combined as a mold assembly, andthe polymerized reaction product can comprise a polymeric contact lensbody.

In another example, the water-soluble vinyl alcohol copolymer can be acopolymer for which 50 grams or more of the copolymer are visiblysoluble in 1 liter of deionized water at 20 degrees C.

In another example, a sample of the water-soluble vinyl alcoholcopolymer, when agitated, can dissolve at least 40% (wt/wt) in 1 literof deionized water at 30 degrees C. in 20 minutes or less.

In another example, a sample of the water-soluble vinyl alcoholcopolymer can dissolve in deionized water leaving less than 15% (wt/wt)of the sample remaining as insoluble solids once the soluble portion ofthe sample has dissolved.

In another example, a solution of the at least one water-soluble vinylalcohol copolymer can have a viscosity which varies less than about 20%when stored at a temperature of about 90° C. or less over a period of atleast about 12 hours.

In another example, the rate of oxygen transmittance through a dry filmformed of the water-soluble vinyl alcohol copolymer can be less than 2.0cc 20μ/m² day atm.

In another example, the level of biodegradability of the water-solublevinyl alcohol copolymer can be at least 40% after a standing time ofabout 30 days as determined using test method ISO 14851 with a sample ofabout 600 ml, about 300 ml of standard testing solution, and atemperature of about 25 degrees C.

In another example, a sample of the dry water-soluble vinyl alcoholcopolymer can have a percent haze of less than 30%.

In another example, the at least one water-soluble vinyl alcoholcopolymer can have a level of UV light transmittance less than 15%.

In another example, the water-soluble vinyl alcohol copolymer can be avinyl alcohol copolymer essentially free of ethylene units.

In yet another example, the at least one water-soluble vinyl alcoholcopolymer can comprise or consist of NICHIGO G-POLYMER™ (Nippon Gohsei,Osaka, Japan).

A method of the present disclosure can comprise a method wherein thestep of placing the polymerizable composition in one of the first moldmember or the second mold member comprises placing a polymerizablecomposition comprising at least one silicon-containing monomer and atleast one hydrophilic monomer in the first mold member, and wherein theophthalmic device body comprises a silicone hydrogel ophthalmic devicebody.

A method of the present disclosure can comprise a method wherein thestep of using the at least one water-soluble vinyl alcohol copolymer toform at least one of the first mold member and the second mold membercomprises completely forming a molding surface of at least one of thefirst mold member and the second mold member by injection molding.

A method of the present disclosure can comprise a method wherein thestep of using the at least one water-soluble vinyl alcohol copolymer toform at least one of the first mold member and the second mold membercomprises injection molding the at least one of the first mold memberand the second mold member, and subsequently lathing at least a portionof a molding surface of the at least one of the first mold member andthe second mold member.

The process of injection molding the water-soluble vinyl alcoholcopolymer can use a process setting selected from the group consistingof: melt temperature from about 180° C. to about 250° C., barreltemperature from about 180° C. to about 250° C., throat temperature fromabout 30° C. to about 70° C., mold tool temperature from about 30° C. toabout 95° C., holding time from about 1 second to about 5 seconds,injection speed from about 50 mm/second to about 250 mm/second,plasticizing speed from about 100 mm/second to about 300 mm/second,injection pressure from about 50 Bar to about 180 Bar, holding pressurefrom about 10 Bar to about 200 Bar, back pressure from about 5 Bar toabout 25 Bar, and any combination thereof. In one example, at least twoof the above process settings can be used. In another example, at leastthree of the above process settings can be used. In yet another example,at least four of the above process settings can be used.

A method of the present disclosure can comprise a method wherein thestep of using the at least one water-soluble vinyl alcohol copolymer toform at least one of the first mold member and the second mold membercomprises using the at least one water-soluble vinyl alcohol copolymerto form a molding surface on the at least one of the first mold memberand the second mold member, a non-molding region of the at least one ofthe first mold member and the second mold member being formed of asecond material, and wherein the step of placing the polymerizablecomposition in the first mold member or the second mold member comprisesplacing the polymerizable composition in direct contact with the moldingsurface comprising the at least one water-soluble vinyl alcoholcopolymer.

A method of the present disclosure can comprise a method wherein theophthalmic device body has ophthalmically acceptably wettable anteriorand posterior surfaces without application of a surface treatment to theophthalmic device body, or without the presence of components in thepolymerizable composition that form an interpenetrating network (IPN) orpseudo-IPN of a hydrophilic polymeric wetting agent in the ophthalmicdevice body during the curing.

A method of the present disclosure can comprise a method wherein themethod further comprises the step of separating the mold assemblyfollowing the curing, and the separating results in the polymericophthalmic device body remaining in contact with one and only one of thefirst mold member and the second mold member, the one and only one ofthe first mold member and the second mold member being the at least oneof the first mold member and the second mold member comprising the atleast one water-soluble vinyl alcohol copolymer, or the separatingresults in the ophthalmic device body being released from both the firstmold member and the second mold member.

A method of the present disclosure can comprise a method wherein thestep of separating the cured mold assembly comprises applying a liquidto the at least one of the first mold member and the second mold membercomprising the at least one water-soluble vinyl alcohol copolymer, andresults in the at least one of the first mold member and the second moldmember comprising the at least one water-soluble vinyl alcohol copolymerat least partially dissolving in the liquid.

A method of the present disclosure can comprise a method wherein themethod further comprises the step of placing the mold assembly includingthe polymeric ophthalmic device body in the ophthalmic device-shapedcavity in a blister package with a packaging solution, and sealing andsterilizing the package, wherein the mold assembly is fully dissolved inthe packaging solution following sterilization.

The present disclosure is also directed to ophthalmic devices castmolded using one or more mold members formed from at least one of thewater-soluble vinyl alcohol copolymers described herein. The ophthalmicdevices can be ocular inserts or contact lenses. The ophthalmic devicescan be silicone hydrogel ophthalmic devices. The ophthalmic devices canbe silicone hydrogel contact lenses.

In one example, the disclosure is directed to a silicone hydrogelcontact lens comprising a cast-molded silicone hydrogel polymericcontact lens body comprising the reaction product of a polymerizablecomposition, the polymerizable composition comprising at least onesilicon-containing monomer and at least one hydrophilic monomer; whereinthe silicone hydrogel polymeric contact lens body is a cast-molded lensbody formed from the polymerizable composition in a mold assemblycomprising a first mold member and a second mold member, at least one ofthe first mold member and the second mold member comprising at least onewater-soluble vinyl alcohol copolymer.

The present disclosure is also directed to packaged ophthalmic devicescast molded using one or more mold members formed from at least one ofthe water-soluble vinyl alcohol copolymers described herein. Thepackaged ophthalmic devices can be packaged ocular inserts or packagedcontact lenses. The packaged ophthalmic devices can be packaged siliconehydrogel ophthalmic devices. The packaged ophthalmic devices can bepackaged silicone hydrogel contact lenses.

In one example, the disclosure is directed to a packaged siliconehydrogel contact lens comprising a blister package formed of ahydrophobic polymer material; a cast-molded silicone hydrogel polymericcontact lens body comprising the reaction product of a polymerizablecomposition, the polymerizable composition comprising at least onesilicone monomer and at least one hydrophilic monomer; and a liquidcomprising the dissolution product of at least one water-soluble vinylalcohol copolymer in an ophthalmically acceptable packaging solution.

The present disclosure is also directed to a mold used for cast moldingan ophthalmic device, including an ocular insert or a contact lens. Themold can comprise a molding surface and a non-molding region, where atleast the molding surface of the mold comprises at least onewater-soluble vinyl alcohol copolymer as described herein. The mold cancomprise a molding surface, or a mold member, or a mold assembly, or asingle-piece mold member configured to mold both an anterior surface anda posterior surface of an ophthalmic device.

Any and all features described herein and any combination of suchfeatures are included within the scope of the present applicationprovided that the features of any such combination are not mutuallyinconsistent. In addition, any feature or combination of features may bespecifically excluded from any example of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart illustrating steps of a method for producing anophthalmic device.

FIG. 2 is a flow chart illustrating certain inputs and outputs of themethod of FIG. 1.

DETAILED DESCRIPTION

It has been discovered that ophthalmic device molds, including ocularinsert molds and contact lens molds, made of at least one water-solublevinyl alcohol copolymer can be used to cast mold polymeric ophthalmicdevice bodies, e.g., polymeric ocular insert device bodies and polymericcontact lens bodies.

As used herein, a vinyl alcohol copolymer is a polymer comprising atleast one unit of a vinyl alcohol functional group and units of afunctional group which is not a vinyl alcohol. This is distinct from avinyl alcohol homopolymer, which is a polymer comprising only repeatingunits of a vinyl alcohol functional group, i.e., poly(vinyl alcohol)(PVOH), or a modified form of PVOH such as a form of PVOH which has beenphysically combined (i.e., not reacted or co-polymerized) withingredients such as plasticizers which modify the properties of thePVOH, such as, for example, the melting temperature to allow the PVOH tobe injection molded.

As used herein, a “water-soluble vinyl alcohol copolymer” is understoodto be a vinyl alcohol copolymer which is visibly soluble in water or anaqueous solution at room temperature (e.g., about 20-25 degrees C.). Forexample, a water-soluble vinyl alcohol copolymer can be a copolymer forwhich 50 grams or more of the copolymer are visibly fully soluble in 1liter of deionized water at 20 degrees C. (i.e., the copolymer issoluble at a level of at least 5% wt/wt in water) as determined using astandard shake flask method as known to persons of ordinary skill in theart. In another example, the water-soluble vinyl alcohol copolymer canbe a copolymer for which 100 grams or more of the copolymer are visiblysoluble in 1 liter of deionized water at 20 degrees C. In anotherexample, the water-soluble vinyl alcohol copolymer can be a copolymerfor which 150 grams or more of the copolymer are visibly soluble in 1liter of deionized water at 20 degrees C. In yet another example, thewater-soluble vinyl alcohol copolymer can be a copolymer for which 200grams or more of the copolymer are visibly soluble in 1 liter ofdeionized water at 20 degrees C.

The water-soluble vinyl alcohol copolymer can rapidly dissolve in wateror an aqueous solution. In one example, when agitated in 1 liter ofdeionized water at 30 degrees C., a sample of the water-soluble vinylalcohol copolymer can dissolve at least 40% (wt/wt) in 20 minutes orless. In another example, when agitated in 1 liter of deionized water at30 degrees C., a sample of the water-soluble vinyl alcohol copolymer candissolve at least 50% (wt/wt) in 20 minutes or less. In yet anotherexample, when agitated in 1 liter of deionized water at 30 degrees C., asample of the water-soluble vinyl alcohol copolymer can dissolve atleast 60% (wt/wt) in 20 minutes or less.

In one example, the water-soluble vinyl alcohol copolymer is a copolymerwhich, when solublized, has a low level of insoluble (i.e., undissolvedand undissolvable) solids present in the solution. For example, when asample of the water-soluble vinyl alcohol copolymer is placed in wateror an aqueous solution, following complete dissolution of the solubleportion of the copolymer, only a small portion of solid copolymermaterial remains. For example, less than about 20% of the amount ofcopolymer by weight, or less than about 15% of the copolymer by weight,or less than about 10% by weight, or less than about 8% by weight, orless than about 6% of the amount of copolymer by weight, or less thanabout 5% of the amount of copolymer by weight can remain as insolublesolids.

In one example, the vinyl alcohol copolymer which, when solublized, hasa low level of insoluble solids present in solution, can dissolve inwater at a temperature from about 30 degrees C. to about 80 degrees C.in less than or equal to 20 minutes to form a 3% (wt/wt) solution of thevinyl alcohol copolymer in water, the solution having a level ofinsoluble solids of about 10% (wt/wt) or less (i.e., 10% by weight ofthe sample of copolymer added to the water remains present as insolublesolids present in the solution). In another example, the vinyl alcoholcopolymer can dissolve in water at a temperature from about 30 degreesC. to about 80 degrees C. in less than or equal to 20 minutes to form a6% (wt/wt) solution of the vinyl alcohol copolymer in water, thesolution having a level of insoluble solids of about 6% (wt/wt) or less.In yet another example, the vinyl alcohol copolymer can dissolve inwater at a temperature from about 30 degrees C. to about 80 degrees C.in less than or equal to 20 minutes to form a 10% (wt/wt) solution ofthe vinyl alcohol copolymer in water, the solution having a level ofinsoluble solids of about 15% (wt/wt) or less.

The solutions of the water-soluble vinyl alcohol copolymer formed bydissolving the molds in a liquid may not present manufacturingdifficulties such as, for example, excessive foaming, gelation of theliquid, or the liquid becoming cloudy due to undissolved or precipitatedcopolymer. For example, the water-soluble vinyl alcohol copolymer of thepresent disclosure can be a water-soluble vinyl alcohol copolymer whichforms physically stable aqueous solutions. An aqueous solution of thewater-soluble vinyl alcohol copolymer may not gel in solution for over 3hours, 6 hours, 12 hours, 24 hours, or 48 hours after formation of thesolution. An aqueous solution of the at least one water-soluble vinylalcohol copolymer described herein can have a viscosity which variesless than about 20%, less than about 15%, or less than about 10% whenstored at a temperature of about 90° C. or less over a period of atleast 12 hours. In another example, a solution of the at least onewater-soluble vinyl alcohol copolymer described herein can be highlyresistant to precipitating when subjected to high shear. The solution ofthe at least one water-soluble vinyl alcohol copolymer can retain itsinitial haze level following mixing in a high shear mixer at 1000 rpmfor 30 minutes at 10° C. In another example, the solution of the atleast one water-soluble vinyl alcohol copolymer can have a haze levelless than +15%, or less than ±10%, or less than ±5% of its initial hazelevel following mixing in a high shear mixer at 1000 rpm for 30 minutesat 10° C. The aqueous solution of the water-soluble vinyl alcoholcopolymer may not foam significantly, i.e., the solution may not foam ata level which becomes disruptive during a “wet” demolding or delensingprocess.

When formed into a dry film, the water-soluble vinyl alcohol copolymercan have a low rate of oxygen transmittance. For example, the rate ofoxygen transmittance through a dry film formed of the copolymer can beless than 2.0 cc 20μ/m² day atm, or less than 1.5 cc 20μ/m² day atm, orless than 1.0 cc 20μ/m² day atm, or less than 0.5 cc 20μ/m² day atm, orless than 0.2 cc 20μ/m² day atm as determined for a dry sample at 20degrees C. In another example, the rate of oxygen transmittance can beless than 0.005 cc 20μ/m² day, or less than 0.004 cc 20μ/m² day, or lessthan 0.003 cc 20μ/m² day. When a water-soluble vinyl alcohol copolymerwith a low rate of oxygen transmittance is used to form a mold memberused to cast mold an ophthalmic device, due to the low level of oxygentransmittance of the mold member, it may be possible to cure theophthalmic device in an oxygen-containing atmosphere without thepresence of oxygen in the atmosphere disrupting the curing process.Thus, in one example, the methods of manufacturing of the presentdisclosure can be methods using mold members formed of the water-solublevinyl alcohol copolymer having low rates of oxygen transmission and caninvolve curing the polymerizable composition in the presence of anoxygen-containing or oxygen-rich atmosphere to form the polymericophthalmic device, although it is also possible to cure thepolymerizable composition in the presence of a low oxygen or essentiallyoxygen-free atmosphere, such as, for example, an atmosphere rich innitrogen gas.

The water-soluble vinyl alcohol copolymer can be biodegradable. Forexample, the water-soluble vinyl alcohol copolymer can have a level ofbiodegradability of at least 40%, or at least 50%, or at least 60%,after a standing time of about 30 days as determined using test methodISO 14851 with a sample of about 600 ml, about 300 ml of standardtesting solution, and a temperature of about 25 degrees C.

The at least one vinyl alcohol copolymer of the present disclosure canbe relatively transparent to visible light. When the transparency of thesolid, dry copolymer is measured as percent haze, the percent haze ofthe copolymer can be less than 30%, or less than 27%, or less than 24%,or less than 22%, or less than 20%, or less than 18%.

The at least one vinyl alcohol copolymer of the present disclosure canhave a relatively low level of UV light transmittance. The UV lighttransmittance through a mold member formed of the copolymer can be lessthan 15% (i.e., more than 85% of the UV light is not transmitted). TheUV light transmittance through the mold member can be less than 10%, orless than 5%, or less than 3%. When mold members formed of the copolymerhaving low UV light transmittance are used in a curing process involvingthe use of UV light, the level of UV light transmitted into thedevice-forming cavity may need to be high, and thus a high level ofincident UV light may need to be applied to the exterior of the moldmember. For example, more than 500 μW, or more than 750 μW, or more than1000 μW, or more than 1200 μW, or more than 1500 μW of UV light can beapplied to the exterior of the mold member during the curing process. Asmany UV light bulbs are known to function best when operating at higherlevels, providing such high incident light levels may allow the UV bulbsto operate more efficiently, increasing bulb life.

The water-soluble vinyl alcohol copolymer, while having good aqueoussolubility, can be practically insoluble in one or more organicsolvents. The term “organic solvent” refers to an organic substancewhich has the ability to solvate or dissolve at least one material. Inone example, the organic solvent can be used to dissolve thewater-soluble vinyl alcohol copolymer. Examples of organic solventsinclude, without limitation, alcohols, e.g., alkanols, such as ethanol,isopropanol and the like, chloroform, butyl acetate, tripropylene glycolmethyl ether, dipropylene glycol methyl ether acetate, and the like andmixtures thereof. For example, the water-soluble vinyl alcohol copolymercan be practically insoluble in ethyl acetate, or can be practicallyinsoluble in benzene, or can be practically insoluble in toluene, or canbe practically insoluble in ethyl acetate, benzene and toluene.

The water-soluble vinyl alcohol copolymer can be a thermoplastic vinylalcohol copolymer, i.e., a vinyl alcohol copolymer that becomes liquidor malleable when heated and freezes to a glassy state when sufficientlycooled, and which can be repeatedly re-melted and re-molded.

The water-soluble vinyl alcohol copolymer be a copolymer can rapidlydissolve in water or an aqueous solution; or can be a copolymer which,when solublized, has a low level of insoluble solids present in thesolution; or can be a copolymer which forms solutions which are notprone to excessive foaming; or can be a copolymer which forms solutionshaving stable viscosities; or can be a copolymer which forms solutionsthat do not precipitate excessively when subjected to high shearconditions; or can be a copolymer which, when formed into a dry film,has a low rate of oxygen transmittance; or can be a copolymer that isbiodegradable; or can be a copolymer that is relatively transparent tovisible light in solid form; or can be a copolymer with a relatively lowlevel of transmittance of UV light; or can be a copolymer that is athermoplastic; or can be any combination thereof.

In one particular example, the water-soluble vinyl alcohol copolymer ofthe present disclosure can be NICHIGO G-POLYMER™ manufactured by NipponGohsei, Osaka, Japan.

The water-soluble vinyl alcohol copolymer can comprise a vinyl alcoholcopolymer with high vinyl alcohol content, or with low vinyl alcoholcontent, i.e., the majority of the units present in the vinyl alcoholcopolymer can be units of a type of vinyl alcohol, or a minority of theunits present in the vinyl alcohol copolymer can be units of a type ofvinyl alcohol, respectively. The water-soluble vinyl alcohol copolymercan be a vinyl alcohol copolymer having a vinyl alcohol unit contentgreater than or equal to about 95%, greater than or equal to about 90%,greater than or equal to about 85%, greater than or equal to about 80%,greater than or equal to about 75%, greater than or equal to about 70%,greater than or equal to about 65%, greater than or equal to about 60%,greater than or equal to about 55%, greater than or equal to about 50%,greater than or equal to about 45%, greater than or equal to about 40%,greater than or equal to about 35%, greater than or equal to about 30%,greater than or equal to about 25%, greater than or equal to about 20%,greater than or equal to about 15%, greater than or equal to about 10%,greater than or equal to about 5%, or less than or equal to about 5%.The percentage of vinyl alcohol units in the polymer chain can beexpressed as on a weight percent basis, or a molar percent basis.

The water-soluble vinyl alcohol copolymer can be a vinyl alcoholcopolymer other than an ethylene-vinyl alcohol copolymer (i.e., thewater-soluble vinyl alcohol copolymer is not comprised of units ofethylene). The water-soluble vinyl alcohol copolymer can be a vinylalcohol copolymer essentially free of ethylene units.

One or more of the water-soluble vinyl alcohol copolymers disclosedherein can be used to form at least one molding surface, or mold member,or mold assembly used to cast mold an ophthalmic device. For example, amolding surface of a mold member can be formed by injection molding thewater-soluble vinyl alcohol copolymer, by machining the water-solublevinyl alcohol copolymer, or by both injection molding and machining thevinyl alcohol copolymer. The machining can comprise lathing, orablating, or both lathing and ablating the water-soluble vinyl alcoholcopolymer to form all or a portion of a molding surface.

The at least one mold surface, or mold member, or mold assembly formedof the water-soluble vinyl alcohol copolymer disclosed herein can be afirst mold member comprising a molding surface configured to mold ananterior surface of an ophthalmic device. The at least one mold memberformed of the water-soluble vinyl alcohol copolymer can be a second moldmember comprising a molding surface configured to mold a posteriorsurface of an ophthalmic device. The at least one mold member formed ofthe water-soluble vinyl alcohol copolymer can be both a first moldmember comprising a molding surface configured to mold an anteriorsurface of an ophthalmic device, and a second mold member comprising amolding surface configured to mold a posterior surface of an ophthalmicdevice. The first mold member and the second mold member can beconfigured to form an ophthalmic device-shaped cavity therebetween whenthe first mold member and the second mold member are combined as a moldassembly.

As used herein, an ophthalmic device can comprise an ocular insert. Anocular insert is a polymeric device which is, during wear, placed incontact with the conjunctiva or with an anterior ocular surface, or thepunctum, or any combination thereof. The anterior ocular surfacecontacted by the ocular insert during wear can comprise the cornea, orthe sclera, or both. In one example, the ocular insert can comprise apunctual plug. An ocular insert may or may not be a transparent device,and may or may not include an optic zone providing vision correction.Optionally, the ocular insert can comprise a drug-delivery device, adiagnostic device, or both. When the ocular insert comprises adrug-delivery device, the drug delivery device can be configured toprovide controlled release of a drug over a pre-determined period oftime such as, for example, 2 hours, or 12 hours, or 24 hours, or oneweek, or one month, or more than one month.

The at least one molding surface, or mold member, or mold assemblyformed of the water-soluble vinyl alcohol copolymer disclosed herein canbe a first mold member comprising a molding surface configured to moldan anterior surface of an ocular insert. The at least one mold memberformed of the water-soluble vinyl alcohol copolymer can be a second moldmember comprising a molding surface configured to mold a posteriorsurface of an ocular insert. The at least one mold member formed of thewater-soluble vinyl alcohol copolymer can be both a first mold membercomprising a molding surface configured to mold an anterior surface ofan ocular insert, and a second mold member comprising a molding surfaceconfigured to mold a posterior surface of an ocular insert. The firstmold member and the second mold member can be configured to form anocular insert-shaped cavity therebetween when the first mold member andthe second mold member are combined as a mold assembly.

As used herein, contact lenses are understood to be polymeric devicesconfigured to be placed or disposed on a cornea of an animal or humaneye. Generally, contact lenses comprise a convex anterior surface, and aconcave posterior surface which may contact the cornea during wear.Contact lenses can be cosmetic lenses or vision correction lenses orboth cosmetic and vision correction lenses. Vision correction lensesinclude a transparent vision correction optic zone. The visioncorrection optic zone can be surrounded by a non-vision correctionperipheral zone which may also be transparent or may include a regionintended to mask, enhance or change eye color or appearance. Cosmeticlenses are lenses intended to mask, enhance or change eye color orappearance, and may or may not be transparent and may or may not includea vision correction optic zone.

The at least one molding surface, or mold member, or mold assemblyformed of the water-soluble vinyl alcohol copolymer disclosed herein canbe a first mold member comprising a concave molding surface configuredto mold an anterior surface of a contact lens. The at least one moldmember formed of the water-soluble vinyl alcohol copolymer can be asecond mold member comprising a convex molding surface configured tomold a posterior surface of a contact lens. The at least one mold memberformed of the water-soluble vinyl alcohol copolymer can be both a firstmold member comprising a concave molding surface configured to mold ananterior surface of a contact lens, and a second mold member comprisinga convex molding surface configured to mold a posterior surface of acontact lens. The first mold member and the second mold member can beconfigured to form a contact lens-shaped cavity therebetween when thefirst mold member and the second mold member are combined as a moldassembly.

In another example, the at least one molding surface, or mold member, ormolding assembly formed of the water-soluble vinyl alcohol copolymer canbe a single-piece mold member (i.e., a unitary mold member used to moldboth an anterior surface and a posterior surface of the ophthalmicdevice). The single-piece mold member can be a mold member formed in onepiece with the device-forming cavity being integral to the mold member.In other words, the device-shaped cavity can be a hollow area integralto the mold member and is not be formed by assembling multiple moldmembers. The single-piece mold member can be configured such that, afterit is formed, at least one port is present in the mold member to allowinjection of monomer into the mold. The single-piece mold member can beconfigured such that, after it is formed, at least one vent is presentin the mold member to allow excess monomer to flow out of the moldmember during or following injection of monomer into the mold. Thesingle-piece mold member can be formed using techniques such as, forexample lost core molding or gas assisted injection molding, which areknown to those of ordinary skill in the art. The use of a single-piecemold member can reduce the amount of monomer required to form theophthalmic device, and, when formed from the water-soluble copolymer,can reduce the physical manipulation required to release the polymericophthalmic device from the single-piece mold member as compared to amold assembly formed from a plurality of mold members, as thesingle-piece mold member can be dissolved in water to release thepolymeric device body, reducing the opportunity for damage to occur tothe device as compared to mechanical methods of releasing the device.Additionally, use of a single-piece mold member may allow themanufacture of ophthalmic devices having unusual geometries which wouldbe more difficult to form using a plurality of mold members.

Unlike molding surface(s) or mold member(s) or a mold assembly (i.e.,mold(s)) made of unmodified PVOH, the mold(s) made of the water-solublevinyl alcohol copolymer described herein can be formed by injectionmolding, or can be formed by compression molding, continuous compressionmolding, thermoforming, etc. Unlike mold(s) made of modified forms ofPVOH, the molds made of the water-soluble vinyl alcohol copolymer can berapidly and completely dissolved in liquids such as water and aqueoussolutions, including water and aqueous solutions at low temperatures.

The process of cast molding contact lens bodies, including siliconehydrogel contact lens bodies, typically begins with the preparation of apair of mold members (i.e., a first mold member and a second moldmember). The mold members can be produced by injection molding athermoplastic polymer mold material into mold shaped cavities, bylathing the polymer mold material to form the entire mold member, or bya combination of injection molding and lathing, for example, injectionmolding to form the basic shape of the mold member and then lathing allor part of the lens forming region of the mold member. For example, afirst portion of the device-forming molding surface can comprise aninjection molded lens-forming molding surface, and a second portion ofthe device-forming molding surface can comprise a machineddevice-forming molding surface. In one such example, the first portionof the lens-forming molding surface can comprises a portion of thelens-forming molding surface molding a peripheral zone and edge of acontact lens, and a second portion of the lens-forming molding surfacecan comprise a portion of the lens-forming molding surface molding anoptic zone of a contact lens.

Typically, when cast molding ophthalmic devices having optical zones,two mold members are combined to form a mold assembly. The two moldmembers are sized and structured to be assembled together to define adevice-shaped cavity therebetween. In the one example, for molding acontact lens, each of the two mold members can comprise either anoptical quality concave lens forming molding surface used to mold ananterior surface of a lens, or a convex optical quality lens formingmolding surface used to mold a posterior surface of a lens. For thepurposes of this disclosure, the mold member with a concave moldingsurface is referred to as a first mold member or a female mold member,and the mold member with a convex molding surface is referred to as asecond mold member or a male mold member. The first and second moldmembers can be structured to form a lens-shaped cavity therebetween whenassembled with each other to form a mold assembly. Alternative moldmember configurations, such as, for example, mold assemblies comprisingmore than two mold members or mold members that are shaped or structureddifferently than described above, can be used with the vinyl alcoholcopolymers described herein. Additionally, the mold members can beconfigured to comprise more than one lens forming region. For example, asingle mold member can be configured to comprise a region configured tomold an anterior lens surface as well as a posterior lens surface, i.e.,to act as either a female or male mold member.

The water-soluble vinyl alcohol copolymer can be used to form at leastone molding surface, or mold member or mold assembly (i.e., at least onemold) for molding polymeric ophthalmic device bodies. The at least onemold can be produced by conventional injection molding procedures knownto persons of ordinary skill in the art. For example, a quantity of thewater-soluble vinyl alcohol copolymer can be heated to form a moltenthermoplastic polymer. The molten thermoplastic polymer can be dispensedinto a mold cavity in the shape of an ophthalmic device mold. In oneexample, the mold cavity can include one or two optical quality contactlens forming molding surfaces. The molding surfaces used to form theoptical quality lens-forming molding surfaces of the mold can beprovided as components of one or more removable inserts located in aplate or other housing, or can be machined as part of the moldingcavity.

In one example, the process settings used to injection mold thewater-soluble vinyl alcohol copolymer of the present disclosure contentcan include:

Melt temperature from about 160° C. to about 250° C.

Barrel temperature from about 160° C. to about 250° C.

Throat temperature from about 30° C. to about 70° C.

Mold tool temperature from about 30° C. to about 95° C.

Holding time from about 1 second to about 5 seconds

Injection speed from about 50 mm/second to about 250 mm/second

Plasticizing speed from about 100 mm/second to about 300 mm/second

Injection pressure from about 50 bar to about 180 bar

Holding pressure from about 10 bar to about 200 bar

Back pressure from about 5 bar to about 25 bar.

For example, at least two of these process settings can be used toinjection mold the vinyl alcohol copolymer. In another example, three,four, five, six, seven, eight, nine, ten, or all of these processsettings can be used to injection mold the vinyl alcohol copolymer. Inone example, the melt temperature can be from about 160° C. to about220° C., and the barrel temperature from about 160° C. to about 220° C.In another example, the melt temperature can be from about 180° C. toabout 250° C., and the barrel temperature from about 180° C. to about250° C.

The at least one mold member can be produced by a combination ofinjection molding and machining, for example, lathing or ablating, wherethe basic shape of the mold is prepared by injection molding, and all ora portion of the device-forming molding surface is prepared by removinga portion of the mold, for example by machining a portion of the mold,such as, for example, all or a part of the region of the mold used tomold an optical zone of an ophthalmic device. In other words, inaccordance with the present disclosure, the device-forming moldingsurfaces of the at least one mold member can be formed completely byinjection molding one or more water-soluble vinyl alcohol copolymers,can be formed completely by machining a portion of at least onewater-soluble vinyl alcohol copolymer, or can be formed by injectionmolding at least one water-soluble vinyl alcohol copolymer to form amold member, a portion of the device-forming molding surface of which issubsequently machined to form the final device-forming molding surfaceof the water-soluble vinyl alcohol copolymer mold member. Thus, in oneexample, injection molding the at least one of the first mold member andthe second mold member can comprise forming a non-molding portion of atleast one of the first mold member and the second mold member byinjection molding, and forming a device-forming molding surface of theat least one of the first mold member and the second mold member bymachining or lathing or ablating or any combination thereof thenon-molding portion of the mold member.

The water-soluble vinyl alcohol copolymer can be used to form at least adevice-forming molding surface of a mold member, where at least some ofthe non-molding regions of the mold member (i.e., regions of the moldwhich are not used to form a surface of a device body) are formed of amaterial other than the water-soluble vinyl alcohol copolymer. In oneexample, a non-molding portion of the mold member can be formed of amaterial that is essentially insoluble in water or aqueous solutions,such as, for example a metal or polymeric material such aspolypropylene. In one example, the non-molding portion can comprise aframe or support for a device-forming molding surface comprising thewater-soluble vinyl alcohol copolymer. The water-soluble vinyl alcoholcopolymer can be used to form the entire device-forming molding surface,or can be used to form a portion of the device-forming molding surface,such as a layer of a multilayer device-forming molding surface, wherethe water-soluble vinyl alcohol copolymer layer is the portion or layerof the multilayer device-forming molding surface that directly contactsthe polymerizable composition during cast molding. The portion or layerof the device-forming molding surface comprising the water-soluble vinylalcohol copolymer can be formed using various methods, such as, forexample, injection molding or film casting.

Regardless of the method used to form the mold member from thewater-soluble vinyl alcohol polymer, the mold member can be used to moldcosmetic contact lenses having a printed design on one of theirsurfaces. These cosmetic contact lenses may or may not have avision-correction zone. Prior to placing the polymerizable compositionin the mold member, a design of any sort can be placed on one or more ofthe lens-forming surfaces of one or more of the mold members to be usedto form the lens. The design printed on the mold member can beconfigured to mask the appearance of the eye, change the appearance ofthe eye, such as, for example, change the appearance of the color of theeye, or enhance the appearance of the eye, such as is done, for example,by a limbal ring.

The design can be printed onto any lens-forming surface of the moldmember, including a concave surface or a convex surface. The design canbe printed onto the lens-forming surface of the mold member using anyprinting method, such as, for example, using ink jet printing, using acliché method, and the like.

The ink or pigment printed onto the mold member can be a water-based inkor pigment vehicle, or can be an organic solvent-based ink or pigmentvehicle.

In one example, due to the use of the water-soluble vinyl alcoholcopolymer to form the mold member onto which the design is printed, asurface treatment such as, for example, a plasma treatment may not needto be applied to the molding surface in order for the design to beprinted with good reproducibility onto the molding surface, although asurface treatment can also be applied. In one example, the ink orpigment vehicle applied to the molding surface of the mold member doesnot bead up when applied to the molding surface. When the polymerizablecomposition is placed in contact with the printed molding surface andsubsequently cured, demolded and delensed, the printing becomesintegrated into the polymeric lens body and remains with the lens bodyfollowing the demolding and delensing.

When forming the single piece mold or molding surface or mold member byinjection molding, the molten thermoplastic polymer in the mold cavitycan then be cooled and separated from the molding surface andsubsequently moved to a station to receive a volume of a polymerizablecomposition to be used to form a polymeric device body.

During the process of manufacturing an ophthalmic device, when the moldmember used to form the device is a single-piece mold member, the volumeof polymerizable composition can be injected directly into the hollowportion of the single-piece mold member. When two or more mold membersare used to mold the device, a volume of polymerizable composition isplaced in one of the mold members before the mold members are combinedto form the mold assembly. Typically this is accomplished by placing apredetermined quantity of the polymerizable composition onto one of themold members, such as, for example, placing the polymerizablecomposition into a concave molding surface of a first mold member. Themold assembly is then assembled by placing another mold member incontact with the first mold member having the polymerizable composition,such as, for example, by placing a convex molding surface of a secondmold member in contact with the first mold member such that adevice-shaped cavity is formed between the first and second moldmembers, the device-shaped cavity containing the polymerizablecomposition. If used, a connection is then formed between first andsecond mold members by whatever means is being used in order to maintainthe mold members in proper alignment during the curing process.

When two or more mold members are combined as a mold assembly, theprocess of assembling the mold members into a mold assembly can furthercomprise the step of forming a connection between the mold members oraffixing the mold members to each other. The mold members can bepermanently affixed to each other, or can be temporarily affixed to eachother. The first mold member and the second mold member can bestructured to be easily separated after being assembled together withoutcausing substantial damage to the polymeric ophthalmic device bodyproduced in the lens shaped cavity.

In one example, the mold members can be configured to form a mechanicalconnection based on the shape of elements of the mold members. Forexample, the mold members can be configured to form an interference fitwhen pressure is applied to one or both of the mold members. In anotherexample, the mold members can both be threaded so as to form aconnection by engaging the interconnecting threads between the moldmembers. Other examples of mechanical connections can include bores andprotrusions between the mold members, or other locking structures.

In another example, the mold members can be affixed to each other usingan adhesive substance placed between the mold members. The adhesivesubstance can comprise or consist of a thermoplastic material. Thethermoplastic material can comprise or consist of the same thermoplasticmaterial used to form at least one of the mold members to be affixed toeach other. For example, a non-molding portion of one or both of thethermoplastic mold members can be deformed or melted in order to affixthe mold members to each other.

In one example, a non-molding portion of one or both of the mold memberscan be heated in order to melt a portion of one or both of the moldmembers to form a weld between the mold members in order to adhere themold members to each other. The weld formed between the mold members cancomprise a single weld located in a single non-molding location betweenthe mold members, for example, a single weld in a single spot in aperipheral region surrounding the device-shaped cavity. The weld formedbetween the mold members can comprise a plurality of welds, each locatedin a single non-molding location between the mold member, for example, 2or 3 or 4 or 5 or more individual welds each formed in a single spot ina peripheral region, where the plurality of welds are positioned aroundthe perimeter of the device-shaped cavity. The plurality of welds can beequidistant from each other around the perimeter of the device-shapedcavity, or can be positioned in a non-symmetric pattern. The weld formedbetween the mold members can comprise a single weld located around theentire perimeter of the lens forming cavity. In such an example,although the thickness of the melted thermoplastic may vary acrossdifferent portions of the weld, a single continuous weld is presentbetween the mold members in an area which completely encircles theperimeter of the device-shaped cavity formed between the mold members.

In another example, a portion of a solvent capable of dissolving one orboth of the mold members can be applied to one or both of the moldmembers in order to dissolve a non-molding portion of one or both of themold members in order to meld a surface of one mold member to a surfaceof the other mold member. As the dissolved mold material re-solidifies,the melded material can act to affix the mold members to each other. Thesolvent can comprise or consist of water or an aqueous solution. Theamount of solvent applied can be a very small portion of the solventsuch as, for example, a few microliters. The solvent can be dropped ontoa surface to be joined, can be sprayed onto a surface to be joined, canbe stamped onto a surface to be joined, etc. For example, one or all ofthe mold members, prior to being placed together to form the moldassembly, can be contacted by a stamp wetted with the solvent. The stampcan be shaped to conform to the shape of the surface to be joined. Forexample, the stamp can be ring-shaped such that, when it contacts anon-molding region of one of the mold members surrounding thedevice-shaped region of the mold member, only the non-molding region ofthe mold member which is intended to be jointed to the other mold memberis wetted. While the solvent is still wet, the mold members can beplaced in contact and melded together. Optionally, pressure can beapplied to the mold assembly to assist in the process of affixing themold members to each other. The pressure can be applied for a period oftime until the mold members have fully melded to each other. Optionally,heat or air can be applied to the assist in melding the mold members anddrying the solvent in order to reduce the amount of time for the meld toform and the melded material to re-solidify, firmly affixing the moldmembers to each other to form the mold assembly.

In the example were a solvent is used to dissolve a portion of a moldmember and form a meld between the mold members, the melded material canbe located in a single non-molding location between the mold members,for example, a single spot in a peripheral region surrounding thedevice-shaped cavity. The melded material can be located in a pluralityof non-molding locations between the mold member, for example, 2 or 3 or4 or 5 or more individual spots in a peripheral region, where theplurality of locations are positioned around the perimeter of thedevice-shaped cavity. The plurality of locations can be equidistant fromeach other around the perimeter of the device-shaped cavity, or can bepositioned in a non-symmetric pattern. The region of melded materialformed between the mold members can be a single continuous regionlocated around the entire perimeter of the device-shaped cavity. In suchan example, although the thickness of the melded thermoplastic may varyacross different portions of the adhered region, a single continuousregion of melded material can be present between the mold members andcan completely encircle the perimeter of the device-shaped cavity formedbetween the mold members.

In another example, an adhesive substance such as a form of glue,contact cement or sealant can be used to form a bond between the moldmembers. In yet another example, the mold members can be joined using anadditional element such as a clip, clamp or bracket. Regardless of thetype of connection used between the mold members, the connection isintended to keep the mold members in alignment during the curingprocess, and can be capable of being released before the demoldingprocess or as part of the demolding process.

When at least one of the molding surfaces or mold members of the moldassembly is formed from a water-soluble material, such as, for example,a water-soluble vinyl alcohol copolymer, the mold members of the moldassembly can be connected in such a manner that the mold members cannotbe released from each other except by at least partially dissolving atleast one of the mold members of the mold assembly. In other words, themold assembly, once formed, can be a non-opening mold assembly whereinthe polymeric device body is released by dissolving all or part of themold members comprising the mold assembly.

The single-piece mold member or the mold assembly having thepolymerizable composition in the device-shaped cavity is then cured.Curing the polymerizable composition in the device-shaped cavity forms apolymerized reaction product in the shape of the device-shaped cavity,i.e., a polymeric device body. Curing typically comprises application ofa form of electromagnetic radiation to the mold assembly including thepolymerizable composition in order to cause polymerization of thepolymerizable composition in the device-shaped cavity of the moldassembly. The form of electromagnetic radiation can comprise thermalradiation, microwave radiation, visible light, ultraviolet (UV) light,etc. Any combination of two or more forms of electromagnetic radiation,as well as two or more levels of one or more forms of electromagneticradiation, can be used to cure the mold assemblies. The method of curingis usually matched to the type of initiator used in the polymerizablecomposition, i.e., a polymerizable composition comprising a UV initiatoris usually cured using UV light, and a polymerizable compositioncomprising a thermal initiator is usually cured using thermal radiation,and usually at a temperature above the initiation temperature of thethermal initiator. Regardless of the method of curing that is used, thetemperature during the curing process can be maintained at a temperaturebelow the melting point of the water-soluble vinyl alcohol copolymer, orbelow the glass transition temperature of the water-soluble vinylalcohol copolymer. The curing process typically involves curing thesingle-piece mold or mold assembly until the polymerizable compositionhas polymerized sufficiently such that the polymeric device body willretain the shape of the device-shaped cavity following demolding anddelensing. As such, the curing process may not result in completereaction of all the polymerizable components of the polymerizablecomposition.

In one example, microwave radiation can be used to cure thepolymerizable composition in a single-piece mold member or in a moldassembly formed from the at least one water-soluble vinyl alcoholcopolymer as described herein. Use of microwave radiation to cure thepolymerizable composition in a mold formed from the water-soluble vinylalcohol copolymer can reduce the amount of time required to cure thecomposition as compared to the use of UV light or thermal radiation(i.e., a heated oven). For example, the time required to cure thepolymerizable composition in a mold formed from the water-soluble vinylalcohol copolymer using microwave radiation can be less than or equal to30 minutes, or less than or equal to 20 minutes, or less than or equalto 15 minutes, or less than or equal to 10 minutes. In another example,the polymerizable composition can comprise a thermal initiator such as,for example, 2,2′-azobiz(isobutyronitrile) (AIBN, VAZO®-64), and thepolymerizable composition can be cured using microwave radiation. Inanother example, the polymerizable composition can comprise a ComfilconA polymerizable composition containing a thermal initiator such as, forexample, AIBN, and the polymerizable composition can be cured usingmicrowave radiation. In yet another example, the polymerizablecomposition can be cured using microwave radiation, and the polymericdevice body can be wet demolded, or wet delensed, or both wet demoldedand wet delensed from the mold member formed from the water-solublevinyl alcohol copolymer. The wet demolding, or the wet delensing, or thewet demolding and delensing can result in the mold member formed fromthe water-soluble vinyl alcohol copolymer at least partially dissolving.In a particular example, the yield of polymeric device bodies from amanufacturing process involving using molds formed from thewater-soluble vinyl alcohol copolymer, curing using microwave radiation,and wet demolding and delensing can be higher than the yield of the samepolymeric device bodies manufactured using the same process but usingmolds formed from a different material such as, for example,polypropylene, or EVOH.

As at least one of the device-forming molding surfaces (of a moldingsurface, a mold member or the mold assembly) is formed of a materialcomprising or consisting of the vinyl alcohol copolymer describedherein, during the process of curing the polymerizable composition toform the polymeric device body, the polymerizable composition is indirect contact with the vinyl alcohol copolymer, and at least onesurface of the resulting ophthalmic device body is thus formed in directcontact with the vinyl alcohol copolymer. In some examples, when all ofthe device-forming molding surfaces comprise the vinyl alcoholcopolymer, all the surfaces of the ophthalmic device are formed indirect contact with the vinyl alcohol copolymer.

When the ophthalmic device is cast molded in a single-piece mold memberformed of the water-soluble vinyl alcohol copolymer, the process ofreleasing the polymeric ophthalmic device from the single-piece moldmember can comprise contacting the single-piece mold member with wateror an aqueous solution and dissolving at least a portion of thesingle-piece mold member.

As used herein, “demolding” refers to the process of separating themolding surfaces or mold members of the mold assembly following curingof the polymerizable composition. As a result of the demolding process,the molding surfaces or mold members are separated from each other, andthe device body remains in contact with, or attached to, or adhered toone and only one of the molding surfaces or mold members used to castmold the device body.

“Dry” demolding processes involve the use of mechanical processes toseparate the molding surfaces or mold members of the mold assembly aftercuring. In dry demolding processes, the mold assembly including thepolymeric device body is not contacted with a liquid, such as an organicsolvent, water or an aqueous solution during the demolding process, andtypically the mold assembly including the polymeric device body has notbeen exposed to a liquid prior to the dry demolding process. Following adry demolding process, the polymeric device body remains in contact withone, and only one, of the molding surfaces or mold members used to moldthe device body. In one example, a dry demolding process may includesqueezing one or more of the molding surfaces or mold members to deformthe molding surface(s) or mold member(s) and to separate the moldingsurfaces or mold members, leaving the polymeric device body in contactwith one of the molding surfaces or mold members. If the moldingsurfaces or mold members of the mold assembly are held together at leastin part by an interference fit between the molding surfaces or moldmembers, a dry demolding process may include applying pressure to one ormore of the molding surfaces or mold members in order to push themolding surfaces or mold members away from each other to break theinterference fit. If the molding surfaces or mold members of the moldassembly are held together at least in part by a weld between themolding surfaces or mold members, dry demolding may include cuttingthrough or breaking apart the welded material.

“Wet” demolding processes involve application of a liquid to separatethe molding surfaces or mold members of the mold assembly after curing.In wet demolding processes, the mold assembly including the polymericdevice body is contacted with a liquid, such as an organic solvent,water or an aqueous solution, during the demolding process. Following awet demolding process, the polymeric device body can remain in contactwith one, and only one, of the molding surfaces or mold members used tomold the device body, or can be released from both of the moldingsurfaces or mold members used to mold the device body. Wet demoldingprocesses may additionally involve the use of mechanical methods ofseparating the molding surfaces or mold members in addition toapplication of liquid to the mold assembly, including squeezing one ormore of the molding surfaces or mold members to deform the moldingsurfaces or mold member(s), applying pressure to one or more of themolding surfaces or mold members in order to push the molding surfacesor mold members away from each other to break an interference fit, orcutting through welds or an adhesive holding the mold assembliestogether. When an additional mechanical separation step is used, it istypically done after first applying the liquid to the mold assembly,such as, for example, dipping or immersing the mold assembly in aliquid.

As part of a wet or dry demolding process, it may be desired to have thedevice body remain in contact with a particular molding surface or moldmember, such as either the first or the second mold member, followingthe demolding process. In order to help the device body remain incontact with the desired molding surface or mold member, heat can beapplied to the first or second molding surface or mold member, forexample, by blowing heated air on the back of the molding surface ormold member. Alternatively, the first or second molding surface or moldmember can be chilled, for example by blowing chilled air on the back ofthe molding surface or mold member or applying a chilled liquid to oneof the molding surfaces or mold members. An application of pressure toeither the first or second molding surface or mold member beforedemolding or concurrently with the demolding process can also help thedevice body to remain in contact with a particular molding surface ormold member (i.e., the first or second molding surface or mold member)following the demolding process. In one example, when it is desired tohave the polymeric device body remain in contact with the second moldingsurface or mold member at the end of the demolding process, heat can beapplied to the back of the first molding surface or mold memberimmediately before or during the demolding process. The heat can beapplied at a temperature below the melting point of the molding surfaceor mold member. The heat can be applied for a short amount of time suchas, for example, less than or equal to 15 seconds, or less than or equalto 10 seconds, or less than or equal to 5 seconds.

“Delensing” refers to the process of releasing the device body from theone molding surface or mold member with which the device body remains incontact after the molding surfaces or mold members of the mold assemblyhave been separated in a demolding process. As used herein, “delensing”may refer to a process involving any ophthalmic device body, includingan ocular insert body or a contact lens body.

“Dry” delensing processes involve the use of mechanical processes torelease the device body from the one remaining molding surface or moldmember with which the device body is in contact following the demoldingstep. In dry delensing processes, the device body and the one remainingmolding surface or mold member with which the device body is in contactare not contacted by a liquid, such as an organic solvent, water or anaqueous solution, as part of the delensing process. While it is possiblethat a wet demolding process (involving application of a liquid to amold assembly including a polymeric device body) may be used prior to adry delensing process, it is more common to use a dry demolding processprior to a dry delensing process. When a dry demolding process and a drydelensing process are used together, the device body has not beenexposed to a liquid, for example an organic solvent, water or an aqueoussolution, until after the device body has been released from bothmolding surfaces or mold members of the mold assembly (i.e., releasedfrom both the first and second molding surfaces and mold members). Inone example, a dry delensing process may involve the use of a vacuumapparatus to lift the polymeric device body from the one remainingmolding surface or mold member with which it was in contact followingthe demolding step. A dry delensing process may also involve squeezingthe one remaining molding surface or mold member to at least partiallybreak the bond between the one molding surface or mold member and thelens body. A dry delensing process may involve blowing air between theedge of the device body and the molding surface or mold member to atleast partially break the bond between the device body and the moldingsurface or mold member. A dry delensing process may involve inserting aprying tool between the edge of the device body and the molding surfaceor mold member to at least partially break the bond between the devicebody and the molding surface or mold member.

Following dry demolding and dry delensing, the polymeric device bodiesmay be washed (e.g., rinsed or extracted or hydrated or any combinationthereof) either in an organic solvent-based liquid, or in a liquidessentially free of an organic solvent. Alternatively, following drydemolding and dry delensing, the polymeric device body can be placeddirectly into a package with a packaging solution, sealed, andsterilized.

“Wet” delensing processes involve the application of a liquid such as anorganic solvent, water or an aqueous solution to release the device bodyfrom the one remaining molding surface or mold member with which thedevice body is in contact following the demolding step. After orconcurrently with application of the liquid, a wet delensing process canfurther comprise using a vacuum apparatus to lift the polymeric devicebody from the one remaining molding surface or mold member with which itwas in contact following the demolding step. Optionally, a wet delensingprocess may also include using mechanical means to assist in releasingthe device body, such as, for example, squeezing the one remainingmolding surface or mold member to at least partially break the bondbetween the one molding surface or mold member, blowing air between theedge of the device body and the molding surface or mold member, orinserting a prying tool between the edge of the device body and themolding surface or mold member to at least partially break the bondbetween the device body and the molding surface or mold member.

In one example, when dry demolding and dry delensing processes followedby a washing process using a liquid free of an organic solvent are used,or when wet demolding, wet delensing and washing processes using aliquid free of an organic solvent are used, the resulting device bodywill not have been exposed to an organic solvent during themanufacturing process. When such a device body which has not beenexposed to an organic solvent is subsequently placed into a contact lenspackage with a packaging solution, sealed and sterilized, the resultingdevice product will not have been exposed to an organic solvent duringits manufacturing process.

As the vinyl alcohol copolymers disclosed herein are water-soluble, dueto this solubility, when using molding surface(s) or mold member(s)formed from these water-soluble vinyl alcohol copolymers, it is possibleto use wet demolding processes, wet delensing processes, or both wetdelensing and demolding processes involving application of an aqueousliquid to at least partially dissolve the water-soluble vinyl alcoholcopolymer molding surface(s) or mold member(s). In one example of such aprocess, the mold assembly, mold member(s) or molding surface(s)including the polymeric device body can be transferred to a tray beforeapplication of the liquid. The tray can comprise separate recesses sizedand structured to contain the device bodies after the mold assembly,mold member(s) or molding surface(s) are dissolved by the liquid. Forexample, when the entire mold assembly used to mold the device body isformed entirely of the water-soluble vinyl alcohol copolymer, aftercuring, the mold assembly including the polymeric device body can betransferred to the tray. In another example, when the molding surfacesof the mold assembly are formed entirely of the water-soluble vinylalcohol copolymer and the non-molding portions of the mold assembly areformed of a material insoluble in the liquid, the non-molding portionsof the mold assembly can be separated from the molding surfaces of themold assembly, and the molding surfaces of the mold assembly includingthe polymeric device body can be transferred to the tray. In anotherexample, when the molding surfaces of the mold assembly are formedentirely of the water-soluble vinyl alcohol copolymer and thenon-molding portions of the mold assembly are formed of a materialinsoluble in the liquid, the entire molding assembly, including theportions formed of the insoluble material, can be placed in the tray,and the soluble molding surfaces can be allowed to dissolve, releasingthe device body from the mold assembly. The mold portions formed of theinsoluble material, as well as the device body, can then be removed fromthe tray. In yet another example, after demolding, a molding surface ormold member formed entirely of the water-soluble vinyl alcohol copolymerand the attached polymeric device body can be transferred to the tray.

The liquid applied in the wet demolding process, the wet delensingprocess, or both the wet demolding and delensing process can comprisewater or an aqueous solution. In one example, the aqueous solution cancomprise an aqueous solution of a processing aid which increases therate of dissolution of the water-soluble vinyl alcohol copolymer. Inanother example, the processing aid can be a compound that assists inwashing the polymeric device bodies or that assists in the removal of anextractable material from the polymeric device bodies. In yet anotherexample, the processing aid can be a compound that helps protect thedevice body from damage or deformation during processing, such as, forexample, a surfactant, including Tween 80.

The term “surfactant” or refers to a substance which has the ability toreduce the surface tension of water, for example, water or an aqueoussolution in which the substance is present. By reducing the surfacetension of the water, the surfactant facilitates the water containingthe surfactant, when in contact with a polymeric device body which hasnot previously been subjected to extraction processing with an organicsolvent, to more intimately contact the device body and/or moreeffectively wash or remove at least one material present in the devicebody from the device body relative to the water without the surfactantor surfactant component. Generally, a surfactant or surfactant componentdoes not act directly on the at least one material to solvate ordissolve the at least one material. Examples of surfactants include,without limitation, zwitterionic surfactants including forms of betaine,non-ionic surfactants including forms of polysorbate such as polysorbate80, forms of poloxamers or poloxamines, fluorinated surfactants, and thelike and mixtures thereof. In one example, one or more surfactants canbe incorporated into the polymerizable compositions described herein, inwashing liquids described herein, in the packaging solutions describedherein, and any combination thereof.

The process of applying the liquid to dissolve the water-soluble vinylalcohol copolymer molding surface(s), or mold member(s), or moldassembly can include processes which increase the rate of dissolution ofthe copolymer, or which reduce the foaming or gelation of the solutionfollowing dissolution of the copolymer.

In one example, the size or volume of the water-soluble vinyl alcoholcopolymer molding surface(s), or mold member(s), or mold assembly can bereduced prior to applying the liquid to dissolve the copolymer, such as,for example, by cutting off or machining away or ablating a portion ofthe molding surface(s), or mold member(s), or mold assembly.

In another example, before, or during or following or any combinationthereof, the step of applying the liquid, the temperature of the liquidcan be controlled, for example, in order to maintain the liquid at atemperature which increases the rate of dissolution of the water-solublevinyl alcohol copolymer, or at a temperature at which the viscosity ofthe vinyl alcohol copolymer solution remains relatively stable.

In yet another example, the vinyl alcohol copolymer molding surface(s),or mold member(s), or mold assembly can be dissolved using a process orapparatus which cycles fresh solvent over the molding surface(s), ormold member(s), or mold assembly, such as, for example, a Soxhletapparatus.

During or following the step of applying the liquid, the liquid or themolding surface(s) or mold member(s) or mold assembly can be agitated,for example, to increase the rate of dissolution of the vinyl alcoholcopolymer.

During or following the step of applying the liquid, ultrasonic energycan be applied to the liquid, the mold assembly, the mold member(s), orthe molding surface(s). In another example, the ultrasonic energy can beapplied to the liquid and to a mold assembly, mold member(s), or moldingsurface(s) contained in a tray.

The liquid applied to the molding surface(s), or mold member(s), or moldassembly can be applied as part of a wet demolding process, or appliedto a device body and one mold member as part of a wet delensing process,or applied to a device body and a molding surface as part of a wetdelensing process. The temperature of the liquid can be about 90° C. orless, about 80° C. or less, about 70° C. or less, about 60° C. or less,about 50° C. or less, about 40° C. or less, or about 30° C. or less.

The application of the liquid can result in complete dissolution of themolding surface(s) or molding member(s) or mold assembly comprising thewater-soluble vinyl alcohol copolymer in about 240 minutes or less, orin about 180 minutes or less, or in about 120 minutes or less, or inabout 90 minutes or less, or in about 60 minutes or less, or in about 30minutes or less, or in about 20 minutes or less. Alternatively,application of the liquid can result in partial dissolution of themolding surface(s) or mold member(s) or mold assembly comprising thevinyl alcohol copolymer, wherein the partial dissolution is sufficientto separate the mold members of the mold assembly (i.e., to demold themold assembly), to release the lens body from one mold member or fromone molding surface (i.e., to delens the lens body), or both demold anddelens (i.e., completely release the lens body from all the mold membersor molding surfaces used for form it). For example, the application ofliquid can result in greater than 10%, 25%, 50%, 75%, or 90% by weightor volume of the mold assembly or mold member(s) or molding surface(s)being dissolved.

As previously discussed, in some examples, by using the water-solublevinyl alcohol copolymer disclosed herein, demolding, delensing or bothdemolding and delensing processes involving dissolution of thewater-soluble vinyl alcohol copolymer are not severely impacted by someof the problems experienced when dissolving other water-soluble polymersin aqueous solutions. For example, PVOH, when dissolved in aqueoussolutions, can create a large amount of foam, gelation of the solution,a cloudy solution, or any combination of these problems. As the presenceof foam, gels or a cloudy solution can be disruptive to mechanicalprocessing and manufacturing steps, additional measures and expenses arerequired to control or eliminate these problems. Solutions of thewater-soluble vinyl alcohol copolymers described herein that areproduced as part of a wet demolding, delensing or both demolding anddelensing process involving dissolution of mold members comprising thevinyl alcohol copolymer in water or aqueous solutions do not producelarge volumes of foam, even when the liquid and the mold members areagitated. Further, the solutions do not gel easily, making it possibleto conduct the demolding, delensing or both demolding and delensingprocesses in large tanks or baths where a single volume of liquid isapplied to a plurality of lenses and mold members. As the solution doesnot gel under these conditions, it is possible to easily empty thesolution from the tank or bath and re-fill the tank or bath with freshor recycled liquid. As the solution of the water-soluble vinyl alcoholcopolymer in the liquid remains clear, it is possible to observe thelens bodies and the mold members either manually or using an automatedsystem to determine whether or not the lens body has been released fromthe mold member(s) or molding surface(s), or whether or not the moldmember(s) or molding surface(s) have dissolved. As the solution of thewater-soluble vinyl alcohol copolymer can have a higher specific gravitythan the solvent alone, the solution of the copolymer may sink to thebottom of a tank during a dissolution process. The tank used during thedissolution process can be fitted with a drain and a valve at the bottomof the tank in order to remove all or a portion of the copolymersolution from the tank during or following the dissolution process. Thetank used during the dissolution process can be configured to be funnelshaped, in order to direct the heavier copolymer solution to thebottom-most portion of the tank during or following the dissolutionprocess.

Following removal of the copolymer solution formed as part of themanufacturing process, the copolymer solution can be recycled orreclaimed. The recycling or reclaiming process can use the reclaimedcopolymer to re-form ophthalmic mold members, or can use the reclaimedcopolymer for another purpose. For example, the solvent used to dissolvethe copolymer can be evaporated off, resulting in a solid reclaimedcopolymer or a more concentrated copolymer solution.

Following release of the polymeric ophthalmic device body from the moldassembly, e.g., from all the mold members and molding surfaces used tocast mold the device body, in one example, the vinyl alcohol copolymermay no longer be present on a surface of the polymeric device body. Inother words, once the device body has been released from the at leastone mold member comprising the at least one vinyl alcohol copolymer, alayer of the at least one vinyl alcohol copolymer may not remain on asurface of the device body. The release of the device body from the atleast one mold member can comprise a dry demolding step or a drydelensing step or a wet demolding step or a wet delensing step.Following release of the device body from the at least one mold membercomprising the at least one vinyl alcohol copolymer, a portion of the atleast one vinyl alcohol copolymer may remain present in solution, andthe device body can be present in the solution. However, when the devicebody is present in the solution, the solublized portion of the at leastone vinyl alcohol copolymer may not be chemically or physically attachedor bonded to a surface of the device body, and thus in this example thevinyl alcohol copolymer can be rinsed from the surface of the devicebody using a solution free of the at least one vinyl alcohol copolymer.When the solubilzed vinyl alcohol copolymer can be rinsed from a surfaceof the device body in this manner, it is understood that the portion ofsolublized vinyl alcohol copolymer which may have been in contact with adevice body surface while the device body was present in the solutiondoes not constitute a “layer” of the vinyl alcohol copolymer as usedherein.

Depending upon the type of device body and the demolding/delensingprocesses used, following demolding and delensing, the device body maybe subjected to one or more washing steps, including washing steps in anorganic solvent, an aqueous solution of an organic solvent, water, or anaqueous solution essentially free of an organic solvent. The washingstep can be used to clean dirt or debris from the device bodies, toextract materials from the device bodies, or to hydrate the devicebodies. For example, a washing step can be used to remove diluents fromthe device body, to remove unreacted or partially reacted monomers fromthe device body, or to increase wettability of the device body.

In one example, the washing solution can comprise an organic solvent oran aqueous solution of an organic solvent. The organic solvent cancomprise a volatile organic solvent such as, for example, a volatilealcohol. Examples of volatile alcohols can include lower alcohols, suchas forms of methanol, ethanol, propanol, etc.

As previously discussed, the term “organic solvent” refers to an organicsubstance having the ability to solvate or dissolve at least onematerial. The organic solvent can be used to dissolve unreactedmaterials, diluents and the like, present in a polymeric device bodywhich has not previously been subjected to extraction processing. In oneexample, the material is a material that is not soluble or does notdissolve in water or an aqueous solution. In another example, thematerial is a material that is not as soluble or does not dissolve asmuch in water or an aqueous solution, i.e., the material has increasedsolvation in the organic solvent as compared to water or an aqueoussolution. Thus, the organic solvent in contact with such an unextracteddevice body is effective to solvate or dissolve at least one materialpresent in the device body, or to increase the solvation or dissolve toa greater extent the at least one material present in the device body toreduce the concentration of the at least one material in the devicebody, or to reduce the concentration of the at least one material in thedevice body as compared to a device body treated with water or anaqueous solution. The organic solvent may be used without dilution, thatis 100% organic solvent, or may be used in a composition including lessthan 100% organic solvent, for example and without limitation, anaqueous solution including an organic solvent. In general, an organicsolvent acts, for example, directly acts, on the at least one materialto solvate or dissolve the at least one material.

In another example, the washing solution can comprise water or anaqueous solution essentially free of an organic solvent. The aqueoussolution essentially free of an organic solvent used to wash the presentlenses can include aqueous salt solutions, buffer solutions, surfactantsolutions, wetting agent solutions, comfort agent solutions, anycombination thereof, and the like. In one example, one or more polymericwetting agents or comfort agents can be used to wash the present devicebodies, or in a packaging solution used with the present device bodies.However, it is understood that the present device bodies can haveophthalmically acceptably wettable surfaces when washed or packaged inan aqueous solution that does not contain any polymeric wetting agentsor comfort agents. Thus, while the polymeric wetting agents or comfortagents may be used to increase the wettability of such devices, theirwettability is not dependent solely upon the use of such agents.

Following release of the device body from the molding surface(s) or moldmember(s) or mold assembly and, if used, one or more optional washingsteps, the device body can be placed into a blister package along with aportion of packaging solution. In one example, the blister package cancomprise a hydrophobic polymer. The blister package can then be sealedand sterilized, for example, by autoclaving the package under conditionssuitable for sterilizing the package. Alternatively, when awater-soluble vinyl alcohol copolymer is used to form the moldingsurface(s) or mold member(s) or mold assembly, it is possible to placethe device body and the mold member(s) or molding surface(s) or moldassembly comprising the water-soluble vinyl alcohol copolymer directlyinto the blister package with a portion of solution (without the need todemold, delens or both demold and delens the device body before placingit in the blister package), and have the mold member(s) or moldingsurface(s) or mold assembly comprising the water-soluble vinyl alcoholcopolymer dissolve in the packaging solution during or after themanufacturing process.

In one example, when both the first and second mold members are formedentirely of the water-soluble vinyl alcohol copolymer, after curing, themold assembly including the polymeric device body can be placed into ablister package with a portion of solution, dissolving the mold membersof the mold assembly and avoiding the need to perform separatedemolding, delensing and lens transfer processes. In another example,when molding surfaces of both the first mold member and the second moldmember are formed entirely of the water-soluble vinyl alcohol, aftercuring, the non-molding portions of the mold members can be removed fromthe mold assembly, and the molding surfaces and the device body can beplaced in a blister package with a portion of solution, dissolving themolding surfaces and avoiding the need to perform separate demolding,delensing and lens transfer processes. In another example, when the oneand only one of the first and second mold members to which the devicebody remains attached following demolding is formed entirely of thewater-soluble vinyl alcohol copolymer, after curing and demolding, theone and only one mold member and the attached device body can be placedinto the blister package with a portion of solution, dissolving the oneand only one mold member and avoiding the need to perform separatedelensing and lens transfer processes. In yet another example, when themolding surface of the one and only one of the first and second moldmembers to which the device body remains attached following demoldingcomprises a molding surface formed entirely of the water-soluble vinylalcohol copolymer, after curing, demolding and removing the non-moldingportion of the mold member, the molding surface and the attached devicebody can be placed into the blister package with a portion of solution,dissolving the molding surface and avoiding the need to perform separatedelensing and lens transfer processes. In any of the above examples, thesolution placed in the package and used to dissolve the water-solublevinyl alcohol copolymer can comprise a packaging solution, or cancomprise a solution which is subsequently removed from the package andreplaced with a packaging solution prior to sealing and sterilizing thepackage.

A device can be used to increase the volume of solution used to dissolvethe mold assembly or mold member(s) or molding surface(s) such as thedevice described in PCT Application No. PCT/US11/28197, which is herebyincorporated by reference in its entirety. Alternatively, the devicebody and mold assembly or mold member(s) or molding surface(s) can beplaced in the blister package with a portion of washing solution whichis replaced by packaging solution before the blister package is sealed.Again, a device as described in PCT Application No. PCT/US11/28197 canbe used for this purpose.

The mold assembly or mold members(s) or molding surface(s) comprisingthe water-soluble vinyl alcohol copolymer can dissolve in the portion ofsolution before the blister package is sealed, after the blister packageis sealed, before the blister package is autoclaved, or after theblister package is autoclaved. For example, before sealing the blisterpackage, after sealing the blister package, before autoclaving theblister package, or after autoclaving the blister package, less thanabout 15%, less than about 10%, less than about 5%, or less than about1% by weight of the vinyl alcohol copolymer added to the blister packagecan remain undissolved in the blister package.

In one example, when the molding surface of a mold member is formedentirely of a water-soluble vinyl alcohol copolymer and the non-moldingportion of the mold member is formed of a polymer that is insoluble inwater and the solution, the non-molding portion of the mold member canbe structured to further serve as a blister package. For example, thenon-molding portion of the mold member can be formed of a hydrophobicpolymer, such as, for example, polypropylene. The non-molding portion ofthe mold member can be structured to further comprise a cavity to retaina liquid and a flange extending outwardly from the cavity. In an anotherexample, the non-molding portion of the mold member can be configured toserve as a blister package configured to allow optical inspection of apolymeric device body placed in the blister package. The non-moldingportion of the mold member can be structured to comprise a cavity toretain a liquid, a flange extending outwardly from the cavity and abottom wall surface configured to collimate light. Blister packagesconfigured to allow optical inspection of a lens placed in the blisterpackage are described in U.S. Pat. No. 7,477,366, which is herebyincorporated by reference in its entirety.

In the example where the molding surface of a mold member is formedentirely of a water-soluble vinyl alcohol copolymer and the non-moldingportion of the mold member is configured to serve as a blister package,the method of manufacturing the ophthalmic device can comprise the stepof demolding the mold assembly so that the device body remains incontact with the mold member configured to serve as a blister package.The process can then include adding solution to the cavity of theblister package to dissolve the molding surface formed of thewater-soluble vinyl alcohol copolymer and release the device body fromthe molding surface. The polymeric device body can then be opticallyinspected in the blister package before the blister package is sealedand sterilized.

In the examples where the mold assembly or mold member(s) or moldingsurface(s) formed of the water-soluble vinyl alcohol copolymer contentare dissolved in the packaging solution sealed in the blister packagewith the lens body, the water-soluble vinyl alcohol copolymer cancomprise an ophthalmically acceptable ingredient present in thepackaging solution. In one example, the water-soluble vinyl alcoholcopolymer, when dissolved in the packaging solution, can further serveas a wetting agent, a comfort agent, as an agent that prevents the lensbody from sticking to the blister package, or any combination thereof.

In one example, the method of manufacturing an ophthalmic device asdescribed herein results in a yield of acceptable polymeric devicebodies that is higher than a yield of acceptable polymeric device bodiesmade using an essentially identical method but using first and secondmold members comprising an ethylene vinyl alcohol copolymer instead ofthe at least one water-soluble vinyl alcohol copolymer of the presentdisclosure. The yield of acceptable device bodies can be a yield ofcosmetically acceptable devices, or a yield of ophthalmically acceptabledevices. The yield of acceptable devices can be a yield of devices foundto be free of visually detectable defects as determined by manual visualinspection or by automated inspection using an automated inspectionsystem. The yield of acceptable device bodies can be a yield ofacceptable devices resulting from a particular processing step, such as,for example, a curing step, or a demolding step, or a delensing step, ora washing step, or a packaging step, or any combination of processingsteps.

The water-soluble vinyl alcohol copolymer can be used to cast moldvarious types of polymerizable compositions. The polymerizablecomposition can comprise at least one hydrophilic monomer. Thepolymerizable composition can further comprise at least one crosslinker,or at least one initiator, or at least one tinting agent, or at leastone UV blocker, or any combination thereof. The at least one initiatorcan comprise at least one UV initiator or at least one thermalinitiator. In one example, the hydrophilic monomer can comprise asilicone-free monomer such as, for example, 2-hydroxyethyl methacrylate(HEMA). In another example, the polymerizable composition can furthercomprise at least one silicon-containing monomer. In yet anotherexample, the polymerizable composition can be a polymerizablecomposition which, when polymerized, forms a hydrogel polymericophthalmic device body.

As used herein, the term “hydrogel” refers to a polymeric material,typically a network or matrix of polymer chains, capable of swelling inwater or becoming swollen with water. A hydrogel can also be understoodto be a material that retains water in an equilibrium state. The networkor matrix may or may not be cross-linked. Hydrogels refer to polymericmaterials, including ophthalmic devices, ocular inserts and contactlenses that are water swellable or are water swelled. Thus, a hydrogelmay be (i) unhydrated and water swellable, or (ii) partially hydratedand swollen with water, or (iii) fully hydrated and swollen with water.The hydrogel may be a silicone hydrogel, a silicone-free hydrogel, or anessentially silicone-free hydrogel.

The term “silicone hydrogel” or “silicone hydrogel material” refers to aparticular hydrogel that includes a silicon (Si)-containing component.For example, a silicone hydrogel is typically prepared by combining asilicon-containing monomer with conventional hydrophilic hydrogelprecursors. A silicone hydrogel ophthalmic device is an ophthalmicdevice, including a vision correcting contact lens, which comprises asilicone hydrogel material.

The polymerizable composition can be a polymerizable composition capableof forming a silicone hydrogel polymer when polymerized. The siliconehydrogel polymerizable composition can comprise a) at least onesilicon-containing monomer and b) at least one hydrophilic monomer. Inthe silicone hydrogel polymerizable composition, the at least onehydrophilic monomer can comprise a hydrophilic monomer with an N-vinylgroup. The at least one hydrophilic monomer can comprise a vinyl amide.The at least one silicon-containing monomer of the silicone hydrogelpolymerizable composition can be a silicon-containing monomer having amolecular weight greater than 3,000 daltons. The at least onesilicon-containing monomer can comprise at least two silicon-containingmonomers, each having different numbers of polymerizable groups anddifferent molecular weights. Optionally, the silicone hydrogelpolymerizable composition can further comprise a diluent such as, forexample, a form of silicone oil. In a particular example, the siliconehydrogel polymerizable composition can comprise a Comfilcon Apolymerizable composition, and the polymerized reaction product can be aComfilcon A polymeric lens body.

When the polymerizable composition comprises a silicon-containingmonomer, the composition can further comprise at least one compatiblecrosslinking agent. In particular examples, the silicone-containingcomponent may act as both a crosslinker and as a silicone-containingcomponent. With respect to polymerizable compositions as discussedherein, “compatible” components refers to components which, when presentin a polymerizable composition prior to polymerization, form a singlephase that is stable for a duration of time adequate to allowmanufacture of a polymeric lens body from the composition. For somecomponents, a range of concentrations may be found to be compatible.Additionally, when the polymerizable composition is used to form acontact lens, “compatible” components are components which, whenpolymerized to form a polymeric lens body, produce a lens that hasadequate physical characteristics to be used as a contact lens (e.g.,adequate transparency, modulus, tensile strength, etc.).

“Molecular weight” in the context of a polymer described herein refersto the nominal average molecular mass of a polymer, typically determinedby size exclusion chromatography, light scattering techniques, orintrinsic viscosity determination in 1,2,4-trichlorobenzene. Molecularweight in the context of a polymer can be expressed as either anumber-average molecular weight or a weight-average molecular weight,and in the case of vendor-supplied materials, will depend upon thesupplier. Typically, the basis of any such molecular weightdeterminations can be readily provided by the supplier if not providedin the packaging material. Typically, references herein to molecularweights of monomers, including macromers and pre-polymers, or ofpolymers herein refer to the number average molecular weight. Bothmolecular weight determinations, number-average and weight-average, canbe measured using gel permeation chromatographic or other liquidchromatographic techniques. Other methods for measuring molecular weightvalues can also be used, such as the use of end-group analysis or themeasurement of colligative properties (e.g., freezing-point depression,boiling-point elevation, or osmotic pressure) to determinenumber-average molecular weight or the use of light scatteringtechniques, ultracentrifugation or viscometry to determineweight-average molecular weight.

The hydrophilicity or hydrophobicity of a substance can be determinedusing conventional techniques, such as, for example, based on thesubstance's aqueous solubility. For purposes of the present disclosure,a hydrophilic substance is a substance that is visibly soluble in anaqueous solution at room temperature (e.g. about 20-25 degrees C.). Forexample, a hydrophilic monomer can be understood to be any monomer forwhich 50 grams or more of the monomer are visibly fully soluble in 1liter of water at 20 degrees C. (i.e., the monomer is soluble at a levelof at least 5% wt/wt in water) as determined using a standard shakeflask method as known to persons of ordinary skill in the art. Ahydrophobic substance, as used herein, is a monomer that is visiblyinsoluble in an aqueous solution at room temperature, such thatseparate, visually identifiable phases are present in the aqueoussolution, or such that the aqueous solution appears cloudy and separatesinto two distinct phases over time after sitting at room temperature.For example, a hydrophobic monomer can be understood to be any monomerfor which 50 grams of the monomer are not visibly fully soluble in 1liter of water at 20 degrees C. (i.e., the monomer is soluble at a levelof less than 5% wt/wt in water).

A “monomer” refers to a polymerizable compound, regardless of themolecular weight of the compound. Thus, a monomer can be a low molecularweight monomer, a macromer, or a pre-polymer as described below.

A “low molecular weight monomer” refers to a relatively low molecularweight compound, for example a compound with an average molecular weightless than 700 Daltons that is polymerizable. In one example, a lowmolecular weight monomer can comprise a single unit of a moleculecontaining one or more functional groups capable of polymerizing tocombine with other molecules to form a polymer, the other moleculesbeing of the same structure or different structures as the low molecularweight monomer.

A “macromer” refers to medium and high molecular weight compounds orpolymers, which can contain one or more functional groups capable ofpolymerization or further polymerization. For example, a macromer can bea compound or polymer with an average molecular weight of from about 700Daltons to about 2,000 Daltons.

A “prepolymer” refers to a polymerizable or crosslinkable highermolecular weight compound. A prepolymer, as used herein can contain oneor more functional groups. In one example, a prepolymer can be a seriesof monomers or macromers bonded together such that the overall moleculeremains polymerizable or crosslinkable. For example, a prepolymer can bea compound with an average molecular weight greater than about 2,000Daltons.

A “polymer” refers to a material formed by polymerizing one or moremonomers, macromers, prepolymers or mixtures thereof. As used herein, apolymer is understood to refer to a molecule that is not capable ofbeing polymerized, but is capable of being crosslinked to otherpolymers, for example, to other polymers present in a polymerizablecomposition or during the reaction of monomers, macromers and/orprepolymers to form other polymers in a polymerizable composition.

A “network” of a hydrophilic polymer typically means that crosslinks areformed between polymer chains by covalent bonds or by physical bonds,e.g. hydrogen bonds. A network can include two or more polymericcomponents, and can include an interpenetrating network (IPN) in whichone polymer is physically entangled with a second polymer such thatthere are few, if any, covalent bonds between them, but the polymerscannot be separated from each other without destroying the network.

An “interpenetrating network” or “IPN” refers to a combination of two ormore different polymers, in network form, of which at least one issynthesized (e.g., polymerized) and/or cross-linked in the presence ofthe other without or substantially without any covalent bonds betweenthem. An IPN can be composed of two kinds of chains forming two separatenetworks, but in juxtaposition or interpenetrating. Examples of IPNsinclude sequential IPNs, simultaneous IPNs, and homo-IPNs.

A “pseudo-IPN” refers to a polymeric reaction product where at least oneof the different polymers is cross-linked while at least one otherpolymer is non-crosslinked (e.g. linear or branched), wherein thenon-cross-linked polymer is distributed in and held by the cross-linkedpolymer on a molecular scale such that the non-cross-linked polymer issubstantially unextractable from the network.

Hydrophilic Monomers. Hydrophilic monomers, including silicon-freehydrophilic monomers, are included in the polymerizable compositionsused to make the present silicone hydrogels. The silicon-freehydrophilic monomers exclude hydrophilic compounds that contain one ormore silicon atoms. Hydrophilic monomers can be used in combination withsilicon-containing monomers, macromers or prepolymers in thepolymerizable compositions to form silicone hydrogels. In siliconehydrogels, hydrophilic monomer components include those that are capableof providing at least about 10% (w/w), or even at least about 25% (w/w)water content to the resulting hydrated lens when combined with theother polymerizable composition components. For silicone hydrogels, thetotal hydrophilic monomers can be from about 25% (w/w) to about 75%(w/w), or from about 35% (w/w) to about 65% (w/w), or from about 40%(w/w) to about 60% (w/w), of the polymerizable composition.

Monomers that may be included as the hydrophilic monomers typicallypossess at least one polymerizable double bond, at least one hydrophilicfunctional group, or both. Examples of polymerizable double bondsinclude, for example, vinyl, acrylic, methacrylic, acrylamido,methacrylamido, fumaric, maleic, styryl, isopropenylphenyl,O-vinylcarbonate, O-vinylcarbamate, allylic, O-vinylacetyl and N-vinyllactam and N-vinylamido double bonds. In one example, the hydrophilicmonomers are vinyl-containing (e.g., an acrylic containing monomer or anon-acrylic vinyl containing monomer). Such hydrophilic monomers maythemselves be used as crosslinking agents.

Hydrophilic vinyl-containing monomers that may be incorporated into thematerials of the present lenses include, without limitation, thefollowing: N-vinyl lactams (e.g. N-vinyl pyrrolidone (NVP)),N-vinyl-N-methyl acetamide (VMA), N-vinyl-N-ethyl acetamide,N-vinyl-N-ethyl formamide, N-vinyl formamide, N-2-hydroxyethyl vinylcarbamate, N-carboxy-β-alanine N-vinyl ester and the like and mixturesthereof. One example of a vinyl-containing monomer is N-vinyl-N-methylacetamide (VMA). The structure of VMA corresponds toCH₃C(O)N(CH₃)—CH═CH₂. Hydrophilic monomers which may be incorporatedinto the polymerizable composition also include hydrophilic monomerssuch as N,N-dimethyl acrylamide (DMA), 2-hydroxyethyl acrylate, glycerolmethacrylate, 2-hydroxyethyl methacrylamide, N-vinylpyrrolidone (NVP),and polyethyleneglycol monomethacrylate. In certain examples,hydrophilic monomers including DMA, NVP and mixtures thereof areemployed.

In accordance with the present disclosure, a cross-linking agent isunderstood to be a monomer having more than one polymerizable functionalgroup as part of its molecular structure, such as two or three or fourpolymerizable functional groups, i.e., a multifunctional monomer such asa bifunctional or trifunctional or tetrafunctional monomer. One or morenon-silicon cross-linking agents that can be used in the polymerizablecompositions disclosed herein include, for example, without limitation,allyl (meth)acrylate, or lower alkylene glycol di(meth)acrylate, orpoly(lower alkylene) glycol di(meth)acrylate, or lower alkylenedi(meth)acrylate, or divinyl ether, or divinyl sulfone, or di- andtrivinylbenzene, or trimethylolpropane tri(meth)acrylate, orpentaerythritol tetra(meth)acrylate, or bisphenol A di(meth)acrylate, ormethylenebis(meth)acrylamide, or triallyl phthalate, or diallylphthalate, or ethylene glycol dimethacrylate (EGDMA), or triethyleneglycol dimethacrylate (TEGDMA), or triethylene glycol divinyl ether(TEGDVE), or trimethylene glycol dimethacrylate (TMGDMA), or anycombination thereof. In one example, the cross-linking agent can have amolecular weight less than 1500 daltons, or less than 1000 daltons, orless than 500 daltons, or less than 200 daltons. Typically, thecrosslinking agents are present in the polymerizable silicone hydrogelcomposition in relatively small total amounts in the polymerizablecomposition, such as in an amount ranging from about 0.1% (w/w) to about10% (w/w), or from about 0.5% (w/w) to about 5% (w/w), or from about0.75% (w/w) to about 1.5% (w/w), by weight of the polymerizablecomposition.

In some examples, one or more of the monomers may comprise crosslinkingfunctionality (i.e., the monomer may be multi-functional). In suchcases, the use of an additional crosslinker in addition to the monomer,macromer or prepolymer with crosslinking functionality is optional, andthe monomer, macromer or prepolymer with crosslinking functionality maybe present in the polymeriziable silicone hydrogel composition in alarger amount, such as, for example, at least about 3% (w/w), at leastabout 5% (w/w), at least about 10% (w/w), or at least about 20% (w/w).

Useful silicon-containing components comprise polymerizable functionalgroups such as vinyl, acrylate, methacrylate, acrylamide,methacrylamide, N-vinyl lactam, N-vinylamide, and styryl functionalgroups. The polymerizable compositions as described herein can be basedon a silicon-containing monomer, including a silicon-containing lowmolecular weight monomer, or a silicon-containing macromer, or asilicone-containing prepolymer, or any combination thereof, and ahydrophilic monomer or co-monomer, and a crosslinking agent. In oneexample, the polymerizable composition of the present disclosure cancomprise at least two silicon-containing monomers, each having adifferent molecular weight. Examples of silicon-containing componentsthat may be useful in the present lenses can be found in U.S. Pat. Nos.3,808,178, 4,120,570, 4,136,250, 4,139,513, 4,153,641, 4,740,533,5,034,461, 5,496,871, 5,959,117, 5,998,498, 5,981,675, and 5,998,498;U.S. Pat. Application Publication Nos. 2007/0066706, 2007/0296914,2008/0048350, 2008/0269429, and 2009/0234089; and Japanese patentapplication publication number 2008-202060A, all of which areincorporated in their entireties herein by reference.

The polymerizable compositions for use as described herein may includeone or more hydrophobic monomers, including silicon-free hydrophobicmonomers. Examples of such silicon-free hydrophobic monomers include,without limitation, acrylic and methacrylic acids and derivativesthereof, including methylmethacrylate, Any combination of two or morehydrophobic monomers may be employed.

Illustrative acrylic monomers which can be used in the polymerizablecomposition include N,N-dimethylacrylamide (DMA), 2-hydroxyethylacrylate, glycerol methacrylate, 2-hydroxyethyl methacrylate (HEMA),methacrylic acid, acrylic acid, methylmethacrylate (MMA), ethyleneglycol methyl ether methacrylate (EGMA), and any mixtures thereof. Inone example, the total acrylic monomer content is in an amount rangingfrom about 5% (w/w) to about 50% (w/w) of the polymerizable compositionused to prepare a silicone hydrogel lens product, and can be present inan amount ranging from about 10% (w/w) to about 40% (w/w), or from about15% (w/w) to about 30% (w/w), of the polymerizable composition.

Additional Hydrogel Components. The polymerizable compositions used inthe lenses and in the methods described herein can also includeadditional components, e.g., one or more initiators, such as one or morethermal initiators, one or more ultraviolet (UV) initiators, visiblelight initiators, any combination thereof, and the like, one or more UVabsorber agents or compounds, or UV radiation or energy absorber,tinting agent, pigments, release agents, antimicrobial compounds, and/orother additives. The term “additive” in the context of the presentdisclosure refers to a compound or any chemical agent provided in thepresent hydrogel contact lens polymerizable compositions or thepolymerized hydrogel contact lens products, but which is not necessaryfor the manufacture of a hydrogel contact lens.

The polymerizable compositions may comprise one or more initiatorcompounds, i.e., a compound capable of initiating polymerization of apolymerizable composition. Thermal initiators, i.e., initiators having a“kick-off” temperature, can be used. For instance, exemplary thermalinitiators that can be employed in the present polymerizablecompositions include 2,2′-azobiz(isobutyronitrile) (AIBN, VAZO®-64),2,2′-azobis(2,4-dimethylpentanenitrile) (VAZO®-52),2,2′-Azobis(2-methylbutyronitrile) (VAZO®-67), and1,1′-azobis(cyclohexanecarbonitrile) (VAZO®-88). For VAZO® thermalinitiators, the grade number (i.e., 64, 52, 67, 88, etc.) is the Celsiustemperature at which the half-life of the initiator in solution is 10hours. All of the VAZO® thermal initiators described herein areavailable from DuPont (Wilmington, Del., USA). Additional thermalinitiators, including nitrites as well as other types of initiators, areavailable from Sigma Aldrich. Ophthalmically compatible siliconehydrogel contact lenses can be obtained from polymerizable compositionsthat comprise from about 0.05% (w/w) to about 0.8% (w/w), or from about0.1% (w/w) to about 0.6% (w/w), of VAZO®-64 or other thermal initiator.

The polymerizable compositions may also comprise a demolding aid, thatis to say, one or more ingredients effective in making more facileremoval of the cured contact lenses from their molds. Exemplarydemolding aids include hydrophilic silicones, polyalkylene oxides, andany combination thereof. The polymerizable compositions may additionallycomprise a diluent selected from the group consisting of hexanol,ethoxyethanol, isopropanol (IPA), propanol, decanol and any combinationthereof. Diluents, if employed, are typically present in amounts rangingfrom about 10% (w/w) to about 30% (w/w). Compositions having relativelyhigher concentrations of diluents tend to, but do not necessarily, havelower ionoflux values, reduced modulus, and increased elongation, aswell as water break up times (WBUTs) greater than 20 seconds. Additionalmaterials suitable for use in making hydrogel contact lenses aredescribed in U.S. Pat. No. 6,867,245, the disclosure of which isincorporated in its entirety herein by reference. In certain exampleshowever, the polymerizable composition is diluent-free.

In a particular example of a polymerizable composition, the compositioncomprises a first monomer having a first reactivity ratio, and a secondmonomer having a second reactivity ratio that is less than the firstreactivity ratio. As understood by persons or ordinary skill in the art,a reactivity ratio can be defined as the ratio of the reaction rateconstant of each propagating species adding its own monomer to the rateconstant for its addition of other monomer. Such compositions may alsoinclude at least one cross-linking agent having a reactivity ratiosimilar to the first reactivity ratio or to the second ratio. Suchcompositions may also include at least two crosslinking agents, thefirst crosslinking agent having a reactivity ratio similar to the firstreactivity ratio, and the second crosslinking agent having a reactivityratio similar to the second reactivity ratio. In certain examples, thelens precursor compositions may include one or more removable additives.For example, the polymerizable compositions may include one or morecompatibilizers, demolding aids, delensing aids, wettability enhancers,and ionoflux reducers which are removable.

Silicone hydrogel contact lenses are based on polymerizable lensformulations that include silicon-containing monomers, including lowmolecular weight monomers, macromers, prepolymers or any combinationthereof, and at least one hydrophilic monomer, as previously described.Some examples of silicone hydrogel contact lens materials includematerials having the following USANs: acquafilcon A or aquafilcon B,balafilcon A, comfilcon A, enfilcon A, galyfilcon A, lenefilcon A,lotrafilcon A, lotrafilcon B, senofilcon A, narafilcon A, and filcon II3. In one example, the lens body with ophthalmically acceptably wettableanterior and posterior surfaces without application of a surfacetreatment to the lens body, or without the presence of ainterpenetrating polymeric network (IPN) of a polymeric wetting agent inthe lens body is a comfilcon A silicone hydrogel contact lens body.

Ophthalmic devices comprise bodies that have surfaces, such as ananterior surface and a posterior surface. As used herein, anophthalmically acceptably wettable ophthalmic device is a device havingsurfaces that are all ophthalmically acceptably wettable. Wettabilityrefers to the hydrophilicity of one or more surfaces of a device. Asused herein, a surface of a device can be considered to beophthalmically acceptably wettable if the device receives a score of 3or above in a wettability assay conducted as follows. An ophthalmicdevice is dipped into distilled water, removed from the water, and thelength of time that it takes for the water film to recede from thedevice surface is determined (e.g., water break up time (WBUT)). Theassay grades devices on a linear scale of 1-10, where a score of 10refers to a device in which a drop takes 20 seconds or more to fall fromthe device. A device having a WBUT of more than 5 seconds, such as atleast 10 seconds or more desirably at least about 15 seconds, can be adevice having ophthalmically acceptably wettable surfaces. Wettabilitycan also be determined by measuring a contact angle on one or bothdevice surfaces. The contact angle can be a dynamic or static contactangle, a sessile drop contact angle, a pendant drop contact angle, or acaptive bubble contact angle. Lower contact angles generally refer toincreased wettability of a device surface. For example, anophthalmically acceptably wettable surface of a device can have acontact angle less than about 120 degrees. However, in certain examples,the devices can have a contact angle no greater than 90 degrees, and infurther examples, the device can have an advancing contact angle lessthan about 80 degrees.

The ophthalmic devices cast molded using a water-soluble vinyl alcoholcopolymer disclosed herein can have ophthalmically acceptably wettablesurfaces when fully hydrated, and may not require application of asurface treatment or the presence of an IPN or pseudo-IPN of a polymericwetting agent in the device body in order for the lens to haveophthalmically acceptably wettable surfaces. However, application of asurface treatment to the device or the presence of an IPN or pseudo-IPNof a polymeric wetting agent in the device body can be used to furtherincrease the wettability of the device surfaces above a level that isconsidered ophthalmically acceptably wettable.

An “ophthalmically compatible silicone hydrogel device” refers to asilicone hydrogel ophthalmic device, such as a contact lens, that can beworn on a person's eye without the person experiencing or reportingsubstantial discomfort, including ocular irritation and the like. Whenthe device is a contact lens, such lenses often have an oxygenpermeability, a surface wettability, a modulus, a water content, anionoflux, a design, and any combination thereof, which permit the lensesto be comfortably worn on a patient's eye for extended periods of time,such as for at least a day, at least a week, at least two weeks, orabout a month without requiring removal of the lens from the eye.Typically, ophthalmically compatible silicone hydrogel devices do notcause or are not associated with significant corneal swelling, cornealdehydration (“dry eye”), superior-epithelial arcuate lesions (“SEALs”),or other significant discomfort. Ophthalmically compatible siliconehydrogel contact lenses meet clinical acceptability requirements fordaily wear or extended wear contact lenses.

Ophthalmically compatible silicone hydrogel devices have ophthalmicallyacceptably wettable surfaces, although a device with ophthalmicallyacceptably wettable surfaces may not necessarily be ophthalmicallycompatible. A silicone hydrogel contact device having an “ophthalmicallyacceptably wettable surface” can be understood to refer to a siliconehydrogel device that does not adversely affect the tear film of a devicewearer's eye to a degree that results in the device wearer experiencingor reporting discomfort associated with placing or wearing the siliconehydrogel device on an eye.

A method of manufacturing ophthalmic devices, for example, siliconehydrogel contact lenses, is illustrated in FIG. 1. In accordance withthe present disclosure, all of the steps illustrated in FIG. 1, or asubset of the steps illustrated in FIG. 1 can comprise a method ofmanufacturing contact lenses. Items which serve as inputs, outputs orboth inputs and outputs of the steps of FIG. 1 are illustrated in FIG.2.

FIG. 1 includes a step 102 of providing a water-soluble vinyl alcoholcopolymer of the present disclosure. The water-soluble vinyl alcoholcopolymer is illustrated in FIG. 2 as element 202.

Step 104 of FIG. 1 illustrates the step of using the water-soluble vinylalcohol copolymer to form a single-piece mold member, or to form atleast one of a first mold member and a second mold member, or to form atleast one molding surface of at least one of a first mold member and asecond mold member. Element 204 of FIG. 2 illustrates the resulting moldmember(s) or molding surface(s) comprising the water-soluble vinylalcohol copolymer.

FIG. 1 also includes a step 106 of placing a polymerizable compositionon or in a mold member or molding surface. In reference to the presentdisclosure, the polymerizable composition can be understood to be apolymerizable composition, such as, for example, a silicon-containingpolymerizable composition capable of forming a silicone hydrogel polymerwhen polymerized. The polymerizable composition is illustrated in FIG. 2as element 206. The polymerizable composition may be understood to be apre-polymerized or pre-cured composition suitable for polymerization.

Typically, the polymerizable composition is not polymerized beforecuring or polymerization of the composition. However, polymerizablecompositions may be partially polymerized before undergoing a curingprocess. In some examples, the polymerizable composition may comprise apolymer component which becomes crosslinked with other components of thepolymerizable composition during the curing process. The polymericcomponent can be wetting agent or comfort agent. Alternatively, thepolymeric component can be a polymeric component which is not apolymeric wetting or comfort agent, which does not form aninterpenetrating polymeric network or pseudo-IPN in the lens body, orwhich is neither a polymeric wetting or comfort agent and does not forman IPN or pseudo-IPN in the lens body.

The present polymerizable compositions can be provided in containers,dispensing devices, or mold members prior to a curing or polymerizationprocedure, as described herein. Referring back to FIG. 1, in step 106,the polymerizable composition is placed on a device-forming moldingsurface (i.e., a region used to mold a portion of an ophthalmic devicesuch as a lens surface) of a female mold member or of a male mold. Thefemale mold member can be understood to be a first mold member or ananterior mold member, and the male mold member can be understood to be asecond mold member or a posterior mold member. For example, the femalemold member comprises a molding surface that defines the anterior orfront surface of a lens produced from the lens mold. The second moldmember may be understood to be a male mold member or a posterior moldmember. For example, the second mold member includes a molding surfacethat defines the posterior surface of a device such as a lens producedin the mold member (e.g., the second or male mold member can have aconvex lens forming molding surface).

Further in reference to the present disclosure, at least one of thefirst and second mold members, or a molding surface of at least one ofthe first and second mold members comprises, includes, includes a majoramount of, consists essentially of, or consists of at least onewater-soluble vinyl alcohol copolymer as described herein. In oneexample, the mold member(s) or molding surface(s) as described hereinhave been produced to have molding surfaces with sufficient degrees ofpolarity to produce silicone hydrogel contact lenses havingophthalmically acceptably wettable surfaces. The water-soluble vinylalcohol copolymer can have a polarity from about 1% to about 70%, orfrom about 1% to about 50%, or from about 1% to about 10%, or from about10% to about 45%, or from about 20% to about 40%, or from about 30% toabout 45%, or from about 20% to about 30%.

The average polarity of the polymer can be determined based on theOwens-Wendt-Rabel-Kaebel model, where the contact angle of thethermoplastic polymer is determined using a number of different liquidsof known polarities. The Owens-Wendt-Rabel-Kaebel equation can bewritten in the form of a linear equation, where y is calculated based onthe observed contact angle of each of the different liquids with thepolymer (A) and x is calculated based on the known polar (σ_(L) ^(P))and disperse (σ_(L) ^(D)) components of the total surface energy (σ_(L)^(T)) of each of the different liquids. The data points from thedifferent liquids (x,y) can be plotted, and the linear regression of theplot can then be used to determine the slope (m) and y-intercept (b).The calculated slope and y-intercept can then be used to calculate thepolar (σ_(S) ^(P)) and disperse (σ_(S) ^(D)) components of the totalsurface energy of the polar thermoplastic polymer (σ_(S) ^(T), whereσ_(S) ^(T)=σ_(S) ^(P)+σ_(S) ^(D)).

The Owens-Wendt-Rabel-Kaebel Equation in the form of a linear equation:

$\frac{\sigma_{L}\left( {{\cos \; \theta} + 1} \right)}{2\sqrt{\sigma_{L}^{D}}} = {\frac{\sqrt{\sigma_{S}^{P}}\sqrt{\sigma_{L}^{P}}}{\sqrt{\sigma_{L}^{D}}} + \sqrt{\sigma_{S}^{D}}}$${{{where}\mspace{14mu} y} = \frac{\sigma_{L}\left( {{\cos \; \theta} + 1} \right)}{2\sqrt{\sigma_{L}^{D}}}},{m = \sqrt{\sigma_{S}^{P}}},{x = \frac{\sqrt{\sigma_{L}^{P}}}{\sqrt{\sigma_{L}^{D}}}},{{{and}\mspace{14mu} b} = {\sqrt{\sigma_{S}^{D}}.}}$

Examples of the liquids with different polarities which can be used todetermine average polarity of the polymer include, but are not limitedto, deionized water, diiodomethane, dimethyl sulfoxide (DMSO), andformamide. In selecting the liquids with different polarities, ideally,a number of liquids having a range of polarities based on the liquid'spolar component (σ_(L) ^(P)) of total surface energy would be selected,rather than selecting a number of liquids with different total surfaceenergies (σ_(L) ^(T)). Using this method, the average polarity of thepolymer is calculated by dividing the calculated polar component (σ_(S)^(P)) of total surface energy for the polymer by its calculated totalsurface energy (σ_(S) ^(T)) and multiplying by 100 to obtain the percentpolarity.

To form a mold assembly, the first mold member is placed in contact witha second mold member, forming a device-shaped cavity in the spacebetween the first mold member and the second mold member. The methodillustrated in FIG. 1 includes a step 108 of forming a contact lens moldassembly by placing two contact lens mold members in contact with eachother to form a lens-shaped cavity therebetween. For example, withreference to FIG. 2, following execution of step 108, the polymerizablesilicone hydrogel composition 206 is located in the contact lens-shapedcavity.

At step 110, the method illustrated in FIG. 1 includes curing thepolymerizable composition to form a polymeric device body which iscontained in a mold assembly, as illustrated in FIG. 2 as element 208.At this point in the process, the polymeric lens body has not beenexposed to a liquid. In one example the polymeric lens body can be apolymerized silicone hydrogel contact lens body. During curing, thecomponents of the polymerizable composition polymerize to form apolymeric lens body. Thus, the curing may also be understood to be apolymerizing step. The curing 110 can include exposing the polymerizablelens precursor composition to a form of electromagnetic radiationeffective in polymerizing the components of the lens precursorcomposition. For example, the curing 110 can include exposing thepolymerizable composition to polymerizing amounts of heat, microwaveradiation or ultraviolet (UV) light, among other forms ofelectromagnetic radiation. The curing 110 can also include curing thecompositions in an oxygen-free or nearly oxygen-free environment. Forexample, the curing 110 can occur in the presence of nitrogen or otherinert gases. The curing 110 can be effective to fully polymerize thepolymerizable composition, or can polymerize the polymerizablecomposition to a level such that the lens body when processed (e.g.,demolded, delensed, washed, packaged, sterilized, etc.) is capable ofretaining its molded shape adequately to serve as a contact lens.

A polymeric device body which has not been exposed to a liquid can bepresent at various stages in the manufacturing process, depending uponthe types of demolding and delensing processes used, and whether or notone or more optional washing steps are performed. For example, apolymeric lens body which has not been exposed to a liquid can be apolymeric lens body prior to undergoing a wet demolding process, or awet delensing process, or a wet demolding and delensing process, or anoptional washing process, or any combination thereof. For example, thewashing process can be a cleaning process to remove dust or debris, oran extraction process to remove a portion or substantially all of one ormore extractable components from the polymeric lens body, or a hydrationprocess to partially or fully hydrate the hydrogel lens body, or anycombination thereof. For example, the polymeric lens body which has notbeen contacted by a liquid can comprise a lens body present in a lensshaped cavity of a mold assembly or of two molding surfaces after acuring process, or can comprise a lens body in contact with one and onlyone mold member following a dry demolding process, or can comprise acontact lens body in a tray or other device following dry delensing anddry delensing processes. The polymeric lens body which has not beenexposed to a liquid can include a lens forming component, such as asilicon-containing polymeric network or matrix in the shape of a lens,and a removable component that can be removed from the lens bodyfollowing polymerization. The removable component can be understood toinclude unreacted monomers, oligomers, partially reacted monomers, orother agents which have not become covalently attached or otherwiseimmobilized relative to the lens-forming component. The removablecomponent can also be understood to include one or more additives,including diluents, that can be removed from the polymerized lensproduct during a cleaning, extraction, or hydration procedure, asdiscussed herein. Thus, materials of the removable component can includelinear uncross-linked or slightly cross-linked or branched polymers ofextractable materials that are not cross-linked to or otherwiseimmobilized relative to the polymer backbone, network, or matrix of thelens body.

After curing the polymerizable compositions, the method illustrated inFIG. 1 includes a step 112 of separating the polymeric device body fromthe mold members of the mold assembly. In one example, the process ofseparating the polymeric lens body from the mold member can comprise ademolding process resulting in the polymeric lens body remaining incontact with one, and only one, mold member of the mold members used toform the polymeric lens body. Following the demolding process, thepolymeric lens body is located on, or remains in contact with, just oneof the mold members of the mold assembly. The one and only one moldmember with which the polymeric lens body remains in contact followingdemolding can be the mold member 204 formed using the vinyl alcoholcopolymer 202, or can be a different mold member. When the step 112 ofseparating the polymeric lens body from the mold members comprises ademolding process, the step of separating can further include adelensing step releasing the polymeric lens body from the one and onlyone mold member with which it remained in contact following thedemolding process. The polymeric lens body can be delensed from the malemold member or the female mold member, depending on which mold memberthe polymeric lens body remains in contact with following the demoldingprocess. Alternatively, the step 112 can comprise a combinationdemolding and delensing process, where the lens body is releasedsimultaneously from all of the mold members used to form it. When atleast one of the mold members or molding surfaces used to form the lensbody comprises a water-soluble vinyl alcohol copolymer, the separatingprocess can involve applying a liquid to the lens body and at least onemold member or molding surface (in the form of a mold assembly, a singlemold member, a pair of molding surfaces or a single molding surface, themolding surface(s) being either in contact with, or separated from, thenon-molding portion(s) of the mold member(s)) to at least partiallydissolve the water-soluble vinyl alcohol copolymer and thereby releasethe lens body from the mold assembly, single mold member or moldingsurface(s). The liquid used in a wet separation process can comprisewater or an aqueous solution.

The method illustrated in FIG. 1 optionally includes a step 114 ofwashing the device body. The washing step can comprise contacting apolymeric lens body with a liquid, for example an organic solvent, anorganic solvent solution, water or an aqueous solution free of anorganic solvent, to clean dust or debris from the lens body, or toextract the lens body to remove extractable materials from the lensbody, or to fully or partially hydrate the lens body, or any combinationthereof. In one example, the washing step 114 can comprise a washingstep to remove or dilute the liquid used during a wet demolding process,a wet delensing process, or both. The washing step 114 results in acleaned, extracted or hydrated lens body 210, as shown in FIG. 2. Thewashing step 114 can optionally be conducted on a mold assemblyincluding a polymeric lens body, a polymeric lens body remaining incontact with one mold member, a polymeric lens body which has been fullyreleased from all the molds used to form it, and can be conductedrepeatedly during the manufacturing process.

The washing step 114 can optionally include a step of hydrating thepolymeric device body. The hydrating step can include contacting apolymeric lens body or one or more batches of such polymeric lens bodieswith water or an aqueous solution to form a hydrated lens product, suchas, for example, a silicone hydrogel contact lens. The hydration stepcan fully or partially hydrate the lens body. In one example, thepolymeric lens body which is hydrated in the hydration step is adelensed polymeric lens body which has not been contacted by a liquidprior to the hydration step, or can comprise a polymeric lens body whichhas previously been contacted by a liquid.

After the separating step 112, and the optional washing step 114, themethod illustrated in FIG. 1 can optionally include a step 116 ofpackaging the device body to produce a packaged ophthalmic deviceproduct 212. For example, a lens body can be placed in a blister pack,vial or other suitable container along with a volume of a packagingliquid, such as a saline solution, including buffered saline solutions.In one example, the washing step 114 and packaging step 116 can beconducted simultaneously by placing a polymeric lens body, including apolymeric lens body which has not previously been contacted by a liquid,in a blister package or container with a portion of packaging liquidwhich serves as both a packaging solution and a washing solution. Inanother example, the separating and packaging step can be conductedsimultaneously by placing a polymeric lens body in contact with a moldassembly, two molding surfaces of a mold assembly, a mold member, or amolding surface in a blister package or container with a portion ofpackaging liquid which serves to release the lens body by dissolving thevinyl alcohol copolymer mold member(s) or molding surface(s).

Optionally, the method illustrated in FIG. 1 can further comprise one ormore inspection steps 118. In the example illustrated in FIG. 1, theinspection step is conducted following the packaging step, before thepackage is sealed and sterilized, although the one or more inspectionsteps can be conducted at any point in the process, either before curingor after curing, on a dry device body or a wet device body. For example,an inspection can be performed on one or more mold members to determinethe acceptability of the molding surfaces, can be performed on a moldmember following placing of the polymerizable composition to detect thepresence of bubbles in the polymerizable composition, on a dry lensfollowing curing to determine the acceptability of the dry lens body, oron a wet lens body following separating, washing or packaging todetermine the acceptability of the wet lens body. The result of optionalinspection step(s) 118 as illustrated in FIG. 1 is a packaged inspectedbody 214, but in other processes can comprise an inspected mold member,an inspected polymerizable composition in a mold member, an inspecteddry lens body, or an inspected wet lens body.

Following the step 116 of packaging the device body, the blister pack orcontainer containing the packaged device body 212 can be sealed, andsubsequently sterilized, as shown in optional step 120 of FIG. 1, toproduce a sterilized package comprising an ophthalmic device productsuch as, for example, a contact lens. The packaged device body can beexposed to sterilizing amounts of radiation, including heat such as byautoclaving, gamma radiation, e-beam radiation, ultraviolet radiation,and the like. Depending upon the previous process steps used, thesterilization process can also serve to partially or fully extract,fully hydrate, or both extract and hydrate the packaged device body, orto dissolve the mold member(s) or molding surface(s) comprising thewater-soluble vinyl alcohol copolymer.

The following non-limiting Examples illustrate certain aspects of thepresent methods and devices.

Example 1 Comparative, Theoretical

A quantity of ethylene-vinyl alcohol copolymer is provided in granularor pellet form. A portion of the polymer is processed by conventionalinjection molding into first and second contact lens mold members. Apolymerizable composition for producing silicone hydrogel contact lensesis prepared as described herein, and is used to prepare a plurality ofcast-molded polymerized silicone hydrogel lens bodies as illustrated inFIG. 1. The mold assemblies including the polymerizable composition arecured using thermal or UV radiation. After curing, the mold assembliesincluding the cast-molded polymerized lens bodies are wet or drydemolded to separate the two mold members of the mold assembly.Following the dry demolding step, a wet delensing process is used torelease the polymerized lens bodies from the one mold member with whichthey remain in contact following the demolding step. The released lensbodies are subsequently either washed using a liquid comprising anorganic solvent followed by an aqueous solution essentially free of anorganic solvent, or are washed using an aqueous solution essentiallyfree of an organic solvent. The washing step can include an additionalhydration step, or a separate hydration step can be included before thelens bodies are packaged and sterilized. The yield of acceptable lensbodies is below about 65%.

Example 2 Theoretical

A quantity of water-soluble vinyl alcohol copolymer is provided ingranular or pellet form. A portion of the polymer is processed byconventional injection molding into contact lens mold members. Apolymerizable composition for producing silicone hydrogel contact lensesis prepared as described herein, and is used to prepare a plurality ofcast-molded polymerized silicone hydrogel lens bodies as illustrated inFIG. 1. The mold assemblies including the polymerizable composition arecured using thermal, microwave or UV radiation. After curing, the moldassemblies including the cast-molded polymerized lens bodies are wet ordry demolded to separate the two mold members of the mold assembly.Following the dry demolding step, a wet delensing process is used torelease the polymerized lens bodies from the one mold member with whichthey remain in contact following the demolding step. The released lensbodies are subsequently either washed using a liquid comprising anorganic solvent followed by an aqueous solution essentially free of anorganic solvent, or are washed using an aqueous solution essentiallyfree of an organic solvent. The washing step can include an additionalhydration step, or a separate hydration step can be included before thelens bodies are packaged and sterilized. The yield of acceptable lensbodies is greater than about 75%. When the manufacturing processinvolving minimal handling of the lens body, where the mold assembly isplaced in the blister package and the lens body is demolded and delensedby dissolving the mold assembly in the blister package, followed bywashing the lens body in the blister package, the yield of acceptablelens bodies is greater than about 85%.

Example 3 Theoretical

A quantity of Nichigo G-Polymer™ vinyl alcohol copolymer is provided ingranular or pellet form. A portion of the polymer is processed byconventional injection molding into male and female contact lens moldmembers. A polymerizable composition for producing silicone hydrogelcontact lenses is prepared as described herein, and is used to prepare aplurality of cast-molded polymerized silicone hydrogel lens bodies asillustrated in FIG. 1. The mold assemblies including the polymerizablecomposition are cured using thermal or UV radiation. After curing, themold assemblies including the cast-molded polymerized lens bodies aresimultaneously wet demolded and delensed by placing the mold assemblyincluding the polymeric lens body into a tray, and applying liquid tothe mold assembly to at least partially dissolve the vinyl alcoholcopolymer, thereby releasing the lens body from both molds of the moldassembly. Optionally, the mold assemblies, the mold members, or theliquid can be agitated during the demolding and delensing steps. Thereleased lens bodies are subsequently transferred to a blister packagewith packaging solution, and are sealed and sterilized.

1. A method of manufacturing an ophthalmic device, comprising: (a)providing at least one water-soluble vinyl alcohol copolymer; (b) usingthe at least one water-soluble vinyl alcohol copolymer to form at leastone of a first mold member and a second mold member, the first moldmember comprising a molding surface configured to mold an anteriorsurface of an ophthalmic device and the second mold member comprising amolding surface configured to mold a posterior surface of an ophthalmicdevice, the first mold member and the second mold member configured toform an ophthalmic device-shaped cavity therebetween when combined as amold assembly; (c) placing a polymerizable composition comprising atleast one hydrophilic monomer in the first mold member or the secondmold member; (d) assembling the mold assembly by contacting the firstmold member and the second mold member so as to form the ophthalmicdevice-shaped cavity therebetween with the polymerizable compositioncontained in the ophthalmic device-shaped cavity of the mold assembly;and (e) curing the polymerizable composition in the mold assembly toform a cast-molded polymerized reaction product in the ophthalmicdevice-shaped cavity of the mold assembly, the polymerized reactionproduct comprising a polymeric ophthalmic device body.
 2. The method ofclaim 1, wherein the water-soluble vinyl alcohol copolymer is acopolymer for which 50 grams or more of the copolymer are visiblysoluble in 1 liter of deionized water at 20 degrees C.
 3. The method ofclaim 1, wherein a sample of the water-soluble vinyl alcohol copolymer,when agitated, dissolves at least 40% (wt/wt) in 1 liter of deionizedwater at 30 degrees C. in 20 minutes or less.
 4. The method of claim 1,wherein a sample of the water-soluble vinyl alcohol copolymer dissolvesin deionized water leaving less than 15% (wt/wt) of the sample remainingas insoluble solids once the soluble portion of the sample hasdissolved.
 5. The method of claim 1, wherein a solution of the at leastone water-soluble vinyl alcohol copolymer has a viscosity which variesless than about 20% when stored at a temperature of about 90° C. or lessover a period of at least about 12 hours.
 6. The method of claim 1,wherein the rate of oxygen transmittance through a dry film formed ofthe water-soluble vinyl alcohol copolymer is less than 2.0 cc 20μ/m² dayatm.
 7. The method of claim 1, wherein the level of biodegradability ofthe water-soluble vinyl alcohol copolymer is at least 40% after astanding time of about 30 days as determined using test method ISO 14851with a sample of about 600 ml, about 300 ml of standard testingsolution, and a temperature of about 25 degrees C.
 8. The method ofclaim 1, wherein a sample of the dry, solid water-soluble vinyl alcoholcopolymer has a percent haze of less than 30%.
 9. The method of claim 1,wherein the at least one water-soluble vinyl alcohol copolymer has alevel of UV light transmittance less than 15%.
 10. The method of claim1, wherein the at least one water-soluble vinyl alcohol copolymercomprises NICHIGO G-POLYMER™.
 11. The method of claim 1, wherein thestep of using the at least one water-soluble vinyl alcohol copolymer toform at least one of the first mold member and the second mold membercomprises completely forming a molding surface of at least one of thefirst mold member and the second mold member by injection molding. 12.The method of claim 11, wherein the process of injection molding thewater-soluble vinyl alcohol copolymer uses a process setting selectedfrom the group consisting of: melt temperature from about 180° C. toabout 250° C., barrel temperature from about 180° C. to about 250° C.,throat temperature from about 30° C. to about 70° C., mold tooltemperature from about 30° C. to about 95° C., holding time from about 1second to about 5 seconds, injection speed from about 50 mm/second toabout 250 mm/second, plasticizing speed from about 100 mm/second toabout 300 mm/second, injection pressure from about 50 Bar to about 180Bar, holding pressure from about 10 Bar to about 200 Bar, back pressurefrom about 5 Bar to about 25 Bar, and any combination thereof.
 13. Themethod of claim 1, wherein the step of using the at least onewater-soluble vinyl alcohol copolymer to form at least one of the firstmold member and the second mold member comprises using the at least onewater-soluble vinyl alcohol copolymer to form a molding surface on theat least one of the first mold member and the second mold member, anon-molding region of the at least one of the first mold member and thesecond mold member being formed of a second material, and wherein thestep of placing the polymerizable composition in the first mold memberor the second mold member comprises placing the polymerizablecomposition in direct contact with the molding surface comprising the atleast one water-soluble vinyl alcohol copolymer.
 14. The method of claim1, wherein the method further comprises the step of separating the moldassembly following the curing, and the separating results in thepolymeric ophthalmic device body remaining in contact with one and onlyone of the first mold member and the second mold member, the one andonly one of the first mold member and the second mold member being theat least one of the first mold member and the second mold membercomprising the at least one water-soluble vinyl alcohol copolymer, orthe separating results in the ophthalmic device body being released fromboth the first mold member and the second mold member.
 15. The method ofclaim 14, wherein the step of separating the cured mold assemblycomprises applying a liquid to the at least one of the first mold memberand the second mold member comprising the at least one water-solublevinyl alcohol copolymer, and results in the at least one of the firstmold member and the second mold member comprising the at least onewater-soluble vinyl alcohol copolymer at least partially dissolving inthe liquid.
 16. The method of claim 1, wherein the method furthercomprises the step of placing the mold assembly including the polymericophthalmic device body in the ophthalmic device-shaped cavity in ablister package with a packaging solution, and sealing and sterilizingthe package, wherein the mold assembly is fully dissolved in thepackaging solution following sterilization.
 17. A silicone hydrogelcontact lens, comprising: a cast-molded silicone hydrogel polymericcontact lens body comprising the reaction product of a polymerizablecomposition, the polymerizable composition comprising at least onesilicon-containing monomer and at least one hydrophilic monomer; whereinthe silicone hydrogel polymeric contact lens body is a cast-molded lensbody formed from the polymerizable composition in a mold assemblycomprising a first mold member and a second mold member, at least one ofthe first mold member and the second mold member comprising at least onewater-soluble vinyl alcohol copolymer.
 18. A packaged silicone hydrogelcontact lens, comprising: a blister package formed of a hydrophobicpolymer material; a cast-molded silicone hydrogel polymeric contact lensbody comprising the reaction product of a polymerizable composition, thepolymerizable composition comprising at least one silicone monomer andat least one hydrophilic monomer; and a liquid comprising thedissolution product of at least one water-soluble vinyl alcoholcopolymer in an ophthalmically acceptable packaging solution.
 19. A moldfor cast molding an ophthalmic device, comprising: a mold comprising amolding surface and a non-molding region, wherein at least the moldingsurface of the mold member comprises at least one water-soluble vinylalcohol copolymer.
 20. The mold of claim 19, wherein the mold is asingle-piece mold member configured to mold both an anterior surface anda posterior surface of the ophthalmic device.